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2.5 V to 5.5 V, 400 A, 2-Wire Interface, Quad Voltage Output, 8-/10-/12-Bit DACs AD5306/AD5316/AD5326*
FEATURES AD5306: 4 Buffered 8-Bit DACs in 16-Lead TSSOP A Version: 1 LSB INL, B Version: 0.625 LSB INL AD5316: 4 Buffered 10-Bit DACs in 16-Lead TSSOP A Version: 4 LSB INL, B Version: 2.5 LSB INL AD5326: 4 Buffered 12-Bit DACs in 16-Lead TSSOP A Version: 16 LSB INL, B Version: 10 LSB INL Low Power Operation: 400 A @ 3 V, 500 A @ 5 V 2-Wire (I 2C(R) Compatible) Serial Interface 2.5 V to 5.5 V Power Supply Guaranteed Monotonic by Design over All Codes Power-Down to 90 nA @ 3 V, 300 nA @ 5 V (PD Pin or Bit) Double-Buffered Input Logic Buffered/Unbuffered Reference Input Options Output Range: 0 V to VREF or 0 V to 2 VREF Power-On Reset to 0 V Simultaneous Update of Outputs (LDAC Pin) Software Clear Facility Data Readback Facility On-Chip Rail-to-Rail Output Buffer Amplifiers Temperature Range -40 C to +105 C APPLICATIONS Portable Battery-Powered Instruments Digital Gain and Offset Adjustment Programmable Voltage and Current Sources Programmable Attenuators Industrial Process Control GENERAL DESCRIPTION
The AD5306/AD5316/AD5326 are quad 8-, 10-, and 12-bit buffered voltage output DACs in a 16-lead TSSOP that operate from a single 2.5 V to 5.5 V supply, consuming 500 A at 3 V. Their on-chip output amplifiers allow rail-to-rail output swing with a slew rate of 0.7 V/s. A 2-wire serial interface that operates at clock rates up to 400 kHz is used. This interface is SMBus compatible at VDD < 3.6 V. Multiple devices can be placed on the same bus. Each DAC has a separate reference input that can be configured as buffered or unbuffered. The outputs of all DACs may be updated simultaneously using the asynchronous LDAC input. The parts incorporate a power-on reset circuit, which ensures that the DAC outputs power up to 0 V and remain there until a valid write to the device takes place. There is also a software clear function that clears all DACs to 0 V. The parts contain a power-down feature that reduces the current consumption of the device to 300 nA @ 5 V (90 nA @ 3 V). All three parts are offered in the same pinout, which allows users to select the amount of resolution appropriate for their application without redesigning their circuit board.
FUNCTIONAL BLOCK DIAGRAM
VDD VREFA VREFB GAIN-SELECT LOGIC DAC REGISTER STRING DAC A
AD5306/AD5316/AD5326
LDAC INPUT REGISTER
BUFFER
VOUTA
SCL SDA A1 A0 LDAC INTERFACE LOGIC
INPUT REGISTER
DAC REGISTER
STRING DAC B
BUFFER
VOUTB
INPUT REGISTER
DAC REGISTER
STRING DAC C
BUFFER
VOUTC
INPUT REGISTER POWER-ON RESET
DAC REGISTER
STRING DAC D
BUFFER POWER-DOWN LOGIC
VOUTD
*Protected by U.S. Patent Numbers 5,969,657 and 5,684,481.
VREFD VREFC
PD
GND
REV. C
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GND; CL = 200 pF to GND; all specifications TMIN to TMAX, unless otherwise noted.)
Parameter1 DC PERFORMANCE AD5306 Resolution Relative Accuracy Differential Nonlinearity AD5316 Resolution Relative Accuracy Differential Nonlinearity AD5326 Resolution Relative Accuracy Differential Nonlinearity Offset Error Gain Error Lower Deadband5
3, 4
AD5306/AD5316/AD5326-SPECIFICATIONS
Min A Version2 Typ Max Min B Version2 Typ Max
(VDD = 2.5 V to 5.5 V; VREF = 2 V; RL = 2 k
to
Unit
Conditions/Comments
8 0.15 0.02 10 0.5 0.05 12 2 0.2 5 0.3 10
1 0.25
8 0.15 0.02 10 0.5 0.05 12 2 0.2 5 0.3 10
0.625 0.25
Bits LSB LSB
Guaranteed Monotonic by Design over All Codes
4 0.5
2.5 0.5
Bits LSB LSB
Guaranteed Monotonic by Design over All Codes
16 1 60 1.25 60
10 1 60 1.25 60
Bits LSB LSB mV % of FSR mV
Upper Deadband5
10
60
10
60
mV
Guaranteed Monotonic by Design over All Codes VDD = 4.5 V, Gain = 2; See Figures 2 and 3 VDD = 4.5 V, Gain = 2; See Figures 2 and 3 See Figure 2; lower deadband exists only if offset error is negative. See Figure 3; upper deadband exists only if VREF = VDD and offset plus gain error is positive.
Offset Error Drift6 Gain Error Drift6 DC Power Supply Rejection Ratio6 DC Crosstalk6 DAC REFERENCE INPUTS6 VREF Input Range VREF Input Impedance 148 74 Reference Feedthrough Channel-to-Channel Isolation OUTPUT CHARACTERISTICS6 Minimum Output Voltage7 Maximum Output Voltage7 DC Output Impedance Short Circuit Current Power-Up Time 1 0.25
-12 -5 -60 200 VDD VDD >10 180 90 -90 -75 0.001 VDD - 0.001 0.5 25 16 2.5 5 148 74 1 0.25
-12 -5 -60 200 VDD VDD >10 180 90 -90 -75 0.001 VDD - 0.001 0.5 25 16 2.5 5
ppm of FSR/C ppm of FSR/C dB mV V V MW kW kW dB dB V V W mA mA ms ms VDD = 10% RL = 2 kW to GND or VDD Buffered Reference Mode Unbuffered Reference Mode Buffered Reference Mode and Power-Down Mode Unbuffered Reference Mode. 0 V to VREF Output Range Unbuffered Reference Mode. 0 V to 2 VREF Output Range Frequency = 10 kHz Frequency = 10 kHz This is a measure of the minimum and maximum drive capability of the output amplifier. VDD = 5 V VDD = 3 V Coming out of Power-Down Mode. VDD = 5 V Coming out of Power-Down Mode. VDD = 3 V
LOGIC INPUTS (Excluding SCL, SDA)6 Input Current VIL, Input Low Voltage
1 0.8 0.6 0.5 1.7 3 1.7 3
1 0.8 0.6 0.5
VIH, Input High Voltage Pin Capacitance
mA V V V V pF
VDD = 5 V 10% VDD = 3 V 10% VDD = 2.5 V VDD = 2.5 V to 5.5 V; TTL and 1.8 V CMOS Compatible
-2-
REV. C
AD5306/AD5316/AD5326
Parameter1 LOGIC INPUTS (SCL, SDA) VIH, Input High Voltage VIL, Input Low Voltage IIN, Input Leakage Current VHYST, Input Hysteresis CIN, Input Capacitance Glitch Rejection LOGIC OUTPUT (SDA)6 VOL, Output Low Voltage Three-State Leakage Current Three-State Output Capacitance POWER REQUIREMENTS VDD IDD (Normal Mode)8 VDD = 4.5 V to 5.5 V VDD = 2.5 V to 3.6 V IDD (Power-Down Mode) VDD = 4.5 V to 5.5 V VDD = 2.5 V to 3.6 V 0.3 0.09 1 1 0.3 0.09 1 1 mA mA 2.5
6
Min 0.7 VDD -0.3 0.05 VDD
A Version2 Typ Max VDD + 0.3 0.3 VDD 1 8 50
Min 0.7 VDD -0.3 0.05 VDD
B Version2 Typ Max VDD + 0.3 0.3 VDD 1 8 50
Unit V V mA V pF ns
Conditions/Comments SMBus Compatible at VDD < 3.6 V SMBus Compatible at VDD < 3.6 V See TPC 15 Input filtering suppresses noise spikes of less than 50 ns. ISINK = 3 mA ISINK = 6 mA
8
0.4 0.6 1
8 2.5
0.4 0.6 1
V V mA pF V mA mA
5.5
5.5
500 400
900 750
500 400
900 750
VIH = VDD and VIL = GND. Interface Inactive All DACs in Unbuffered Mode. Buffered Mode, extra current is typically x mA per DAC where x = 5 mA + VREF/RDAC. VIH = VDD and VIL = GND. Interface Inactive IDD = 3 mA (Max) during Readback on SDA IDD = 1.5 mA (Max) during 0 Readback on SDA
NOTES 1 See the Terminology section. 2 Temperature range (A, B Version): -40C to +105C; typical at +25C. 3 DC specifications tested with the outputs unloaded. 4 Linearity is tested using a reduced code range: AD5306 (Code 8 to 255); AD5316 (Code 28 to 1023); AD5326 (Code 115 to 4095). 5 This corresponds to x codes. x = deadband voltage/LSB size. 6 Guaranteed by design and characterization; not production tested. 7 For the amplifier output to reach its minimum voltage, offset error must be negative; for the amplifier output to reach its maximum voltage, V REF = VDD and offset plus gain error must be positive. 8 Interface inactive; all DACs active. DAC outputs unloaded. Specifications subject to change without notice.
AC CHARACTERISTICS1 otherwise noted.)
Parameter2 Output Voltage Settling Time AD5306 AD5316 AD5326 Slew Rate Major-Code Change Glitch Energy Digital Feedthrough Digital Crosstalk Analog Crosstalk DAC-to-DAC Crosstalk Multiplying Bandwidth Total Harmonic Distortion Min
(VDD = 2.5 V to 5.5 V; RL = 2 k
to GND; CL = 200 pF to GND; all specifications TMIN to TMAX, unless
A, B Version3 Typ Max 6 7 8 0.7 12 0.5 0.5 1 3 200 -70 8 9 10
Unit ms ms ms V/ms nV-s nV-s nV-s nV-s nV-s kHz dB
Conditions/Comments VREF = VDD = 5 V 1/4 Scale to 3/4 Scale Change (0x40 to 0xC0) 1/4 Scale to 3/4 Scale Change (0x100 to 0x300) 1/4 Scale to 3/4 Scale Change (0x400 to 0xC00) 1 LSB Change around Major Carry
VREF = 2 V 0.1 V p-p, Unbuffered Mode VREF = 2.5 V 0.1 V p-p, Frequency = 10 kHz
NOTES 1 Guaranteed by design and characterization; not production tested. 2 See the Terminology section. 3 Temperature range (A, B Version): -40C to +105C; typical at +25C. Specifications subject to change without notice.
REV. C
-3-
AD5306/AD5316/AD5326 TIMING CHARACTERISTICS1
Parameter2 t1 t2 t3 t4 t5 t6 3 t7 t8 t9 t10 t11 A, B Version Limit at TMIN, TMAX 2.5 0.6 1.3 0.6 100 0.9 0 0.6 0.6 1.3 300 0 250 0 300 20 + 0.1CB4 20 400 400
(VDD = 2.5 V to 5.5 V; all specifications TMIN to TMAX, unless otherwise noted.)
Unit ms min ms min ms min ms min ns min ms max ms min ms min ms min ms min ns max ns min ns max ns min ns max ns min ns min ns min pF max Conditions/Comments SCL Cycle Time tHIGH, SCL High Time tLOW, SCL Low Time tHD,STA, Start/Repeated Start Condition Hold Time tSU,DAT, Data Setup Time tHD,DAT, Data Hold Time tSU,STA, Setup Time for Repeated Start tSU,STO, Stop Condition Setup Time tBUF, Bus Free Time between a STOP and a START Condition tR, Rise Time of SCL and SDA when Receiving tR, Rise Time of SCL and SDA when Receiving (CMOS Compatible) tF, Fall Time of SDA when Transmitting tF, Fall Time of SDA when Receiving (CMOS Compatible) tF, Fall Time of SCL and SDA when Receiving tF, Fall Time of SCL and SDA when Transmitting LDAC Pulsewidth SCL Rising Edge to LDAC Rising Edge Capacitive Load for Each Bus Line
t12 t13 CB
NOTES 1 See Figure 1. 2 Guaranteed by design and characterization; not production tested. 3 A master device must provide a hold time of at least 300 ns for the SDA signal (referred to the V IH min of the SCL signal) in order to bridge the undefined region of SCL's falling edge. 4 CB is the total capacitance of one bus line in pF. t R and tF measured between 0.3 V DD and 0.7 VDD. Specifications subject to change without notice.
START CONDITION SDA
REPEATED START CONDITION
STOP CONDITION
t9 t 10 t3
SCL
t 11
t4
t4
t6
t2 t5 t7
t1 t8 t 12
LDAC1
t 13 t 12
LDAC2 NOTES
1ASYNCHRONOUS 2SYNCHRONOUS
LDAC UPDATE MODE. LDAC UPDATE MODE.
Figure 1. 2-Wire Serial Interface Timing Diagram
-4-
REV. C
AD5306/AD5316/AD5326
ABSOLUTE MAXIMUM RATINGS 1, 2
(TA = 25C, unless otherwise noted.)
VDD to GND . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 V to +7 V SCL, SDA to GND . . . . . . . . . . . . . . . -0.3 V to VDD + 0.3 V A0, A1, LDAC, PD to GND . . . . . . . . -0.3 V to VDD + 0.3 V Reference Input Voltage to GND . . . . -0.3 V to VDD + 0.3 V VOUTA-D to GND . . . . . . . . . . . . . . . -0.3 V to VDD + 0.3 V Operating Temperature Range Industrial (A, B Version) . . . . . . . . . . . . . -40C to +105C Storage Temperature Range . . . . . . . . . . . . -65C to +150C Junction Temperature (TJ max) . . . . . . . . . . . . . . . . . . . 150C
16-Lead TSSOP Power Dissipation . . . . . . . . . . . . . . . . . . (TJ max - TA)/ JA JA Thermal Impedance . . . . . . . . . . . . . . . . . . . 150.4C/W Reflow Soldering Peak Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . 220C Time at Peak Temperature . . . . . . . . . . . . . 10 sec to 40 sec
NOTES 1 Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those listed in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. 2 Transient currents of up to 100 mA will not cause SCR latch-up.
ORDERING GUIDE
Model AD5306ARU AD5306ARU-REEL7 AD5316ARU AD5316ARU-REEL7 AD5326ARU AD5326ARU-REEL7 AD5306BRU AD5306BRU-REEL AD5306BRU-REEL7 AD5316BRU AD5316BRU-REEL AD5316BRU-REEL7 AD5326BRU AD5326BRU-REEL AD5326BRU-REEL7
Temperature Range -40C to +105C -40C to +105C -40C to +105C -40C to +105C -40C to +105C -40C to +105C -40C to +105C -40C to +105C -40C to +105C -40C to +105C -40C to +105C -40C to +105C -40C to +105C -40C to +105C -40C to +105C
Package Description Thin Shrink Small Outline Package (TSSOP) Thin Shrink Small Outline Package (TSSOP) Thin Shrink Small Outline Package (TSSOP) Thin Shrink Small Outline Package (TSSOP) Thin Shrink Small Outline Package (TSSOP) Thin Shrink Small Outline Package (TSSOP) Thin Shrink Small Outline Package (TSSOP) Thin Shrink Small Outline Package (TSSOP) Thin Shrink Small Outline Package (TSSOP) Thin Shrink Small Outline Package (TSSOP) Thin Shrink Small Outline Package (TSSOP) Thin Shrink Small Outline Package (TSSOP) Thin Shrink Small Outline Package (TSSOP) Thin Shrink Small Outline Package (TSSOP) Thin Shrink Small Outline Package (TSSOP)
Package Option RU-16 RU-16 RU-16 RU-16 RU-16 RU-16 RU-16 RU-16 RU-16 RU-16 RU-16 RU-16 RU-16 RU-16 RU-16
CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the AD5306/AD5316/AD5326 feature proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality.
REV. C
-5-
AD5306/AD5316/AD5326
PIN CONFIGURATION
LDAC 1 VDD 2 VOUTA 3 VOUTB 4
16 A1
13 SDA TOP VIEW VOUTC 5 (Not to Scale) 12 GND
AD5306/ AD5316/ AD5326
15 A0 14 SCL
VREFA 6 VREFB
7
11 V OUTD 10 PD 9
VREFC 8
VREFD
PIN FUNCTION DESCRIPTIONS
Pin No. 1
Mnemonic LDAC
Function Active Low Control Input that Transfers the Contents of the Input Registers to their Respective DAC Registers. Pulsing this pin low allows any or all DAC registers to be updated if the input registers have new data. This allows simultaneous update of all DAC outputs. Alternatively, this pin can be tied permanently low. Power Supply Input. These parts can be operated from 2.5 V to 5.5 V and the supply should be decoupled with a 10 mF capacitor in parallel with a 0.1 mF capacitor to GND. Buffered Analog Output Voltage from DAC A. The output amplifier has rail-to-rail operation. Buffered Analog Output Voltage from DAC B. The output amplifier has rail-to-rail operation. Buffered Analog Output Voltage from DAC C. The output amplifier has rail-to-rail operation. Reference Input Pin for DAC A. It may be configured as a buffered or an unbuffered input depending on the state of the BUF bit in the input word to DAC A. It has an input range from 0.25 V to VDD in unbuffered mode and from 1 V to VDD in buffered mode. Reference Input Pin for DAC B. It may be configured as a buffered or an unbuffered input depending on the state of the BUF bit in the input word to DAC B. It has an input range from 0.25 V to VDD in unbuffered mode and from 1 V to VDD in buffered mode. Reference Input Pin for DAC C. It may be configured as a buffered or an unbuffered input depending on the state of the BUF bit in the input word to DAC C. It has an input range from 0.25 V to VDD in unbuffered mode and from 1 V to VDD in buffered mode. Reference Input Pin for DAC D. It may be configured as a buffered or an unbuffered input depending on the state of the BUF bit in the input word to DAC D. It has an input range from 0.25 V to VDD in unbuffered mode and from 1 V to VDD in buffered mode. Active Low Control Input that Acts as a Hardware Power-Down Option. All DACs go into power-down mode when this pin is tied low. The DAC outputs go into a high impedance state. The current consumption of the part drops to 300 nA @ 5 V (90 nA @ 3 V). Buffered Analog Output Voltage from DAC D. The output amplifier has rail-to-rail operation. Ground Reference Point for All Circuitry on the Part. Serial Data Line. This is used in conjunction with the SCL line to clock data into the 16-bit input shift register. It is a bidirectional open-drain data line that should be pulled to the supply with an external pullup resistor. Serial Clock Line. This is used in conjunction with the SDA line to clock data into the 16-bit input shift register. Clock rates of up to 400 kbit/s can be accommodated in the I2C compatible interface. Address Input. Sets the LSB of the 7-bit slave address. Address Input. Sets the second LSB of the 7-bit slave address.
2 3 4 5 6
VDD VOUTA VOUTB VOUTC VREFA
7
VREFB
8
VREFC
9
VREFD
10
PD
11 12 13
VOUTD GND SDA
14 15 16
SCL A0 A1
-6-
REV. C
AD5306/AD5316/AD5326
TERMINOLOGY Relative Accuracy Major-Code Transition Glitch Energy
For the DAC, relative accuracy or integral nonlinearity (INL) is a measure of the maximum deviation, in LSB, from a straight line passing through the endpoints of the DAC transfer function. Typical INL versus code plots can be seen in TPCs 1, 2, and 3.
Differential Nonlinearity
Major-code transition glitch energy is the energy of the impulse injected into the analog output when the code in the DAC register changes state. It is normally specified as the area of the glitch in nV-s and is measured when the digital code is changed by 1 LSB at the major carry transition (011 . . . 11 to 100 . . . 00 or 100 . . . 00 to 011 . . . 11).
Digital Feedthrough
Differential nonlinearity (DNL) is the difference between the measured change and the ideal 1 LSB change between any two adjacent codes. A specified differential nonlinearity of 1 LSB maximum ensures monotonicity. This DAC is guaranteed monotonic by design. Typical DNL versus code plots can be seen in TPCs 4, 5, and 6.
Offset Error
Digital feedthrough is a measure of the impulse injected into the analog output of a DAC from the digital input pins of the device when the DAC output is not being updated. It is specified in nV-s and is measured with a worst-case change on the digital input pins, i.e., from all 0s to all 1s or vice versa.
Digital Crosstalk
This is a measure of the offset error of the DAC and the output amplifier. It can be positive or negative. See Figures 2 and 3. It is expressed in mV.
Gain Error
This is the glitch impulse transferred to the output of one DAC at midscale in response to a full-scale code change (all 0s to all 1s and vice versa) in the input register of another DAC. It is expressed in nV-s.
Analog Crosstalk
This is a measure of the span error of the DAC. It is the deviation in slope of the actual DAC transfer characteristic from the ideal expressed as a percentage of the full-scale range.
Offset Error Drift
This is a measure of the change in offset error with changes in temperature. It is expressed in (ppm of full-scale range)/C.
Gain Error Drift
This is the glitch impulse transferred to the output of one DAC due to a change in the output of another DAC. It is measured by loading one of the DACs with a full-scale code change (all 0s to all 1s and vice versa) while keeping LDAC high. Then pulse LDAC low and monitor the output of the DAC whose digital code was not changed. The energy of the glitch is expressed in nV-s.
DAC-to-DAC Crosstalk
This is a measure of the change in gain error with changes in temperature. It is expressed in (ppm of full-scale range)/C.
DC Power Supply Rejection Ratio (PSRR)
This indicates how the output of the DAC is affected by changes in the supply voltage. PSRR is the ratio of the change in VOUT to a change in VDD for full-scale output of the DAC. It is measured in dB. VREF is held at 2 V and VDD is varied 10%.
DC Crosstalk
This is the glitch impulse transferred to the output of one DAC due to a digital code change and subsequent output change of another DAC. This includes both digital and analog crosstalk. It is measured by loading one of the DACs with a full-scale code change (all 0s to all 1s and vice versa) with LDAC low and monitoring the output of another DAC. The energy of the glitch is expressed in nV-s.
Multiplying Bandwidth
This is the dc change in the output level of one DAC at midscale in response to a full-scale code change (all 0s to all 1s and vice versa) and output change of another DAC. It is expressed in mV.
Reference Feedthrough
This is the ratio of the amplitude of the signal at the DAC output to the reference input when the DAC output is not being updated (i.e., LDAC is high). It is expressed in dB.
Channel-to-Channel Isolation
The amplifiers within the DAC have a finite bandwidth. The multiplying bandwidth is a measure of this. A sine wave on the reference (with full-scale code loaded to the DAC) appears on the output. The multiplying bandwidth is the frequency at which the output amplitude falls to 3 dB below the input.
Total Harmonic Distortion
This is the ratio of the amplitude of the signal at the output of one DAC to a sine wave on the reference input of another DAC. It is measured in dB.
This is the difference between an ideal sine wave and its attenuated version using the DAC. The sine wave is used as the reference for the DAC, and the THD is a measure of the harmonics present on the DAC output. It is measured in dB.
REV. C
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AD5306/AD5316/AD5326
GAIN ERROR + OFFSET ERROR
OUTPUT VOLTAGE GAIN ERROR + OFFSET ERROR UPPER DEADBAND CODES
OUTPUT VOLTAGE
ACTUAL IDEAL POSITIVE OFFSET ERROR DAC CODE
NEGATIVE OFFSET ERROR
DAC CODE ACTUAL IDEAL
FULL SCALE
Figure 3. Transfer Function with Positive Offset (VREF = VDD)
LOWER DEADBAND CODES AMPLIFIER FOOTROOM
NEGATIVE OFFSET ERROR
Figure 2. Transfer Function with Negative Offset
-8-
REV. C
Typical Performance Characteristics-AD5306/AD5316/AD5326
1.0 TA = 25 C VDD = 5V 0.5
3 TA = 25 C VDD = 5V 2
INL ERROR (LSB)
12 TA = 25 C VDD = 5V
8 INL ERROR (LSB)
INL ERROR (LSB)
1
4 0
0
0 -1
-4
-0.5
-2
-8 -12
0 200 400 600 CODE 800 1000
-1.0
0
50
100
150 CODE
200
250
-3
0
1000
2000 CODE
3000
4000
TPC 1. AD5306 Typical INL Plot
TPC 2. AD5316 Typical INL Plot
TPC 3. AD5326 Typical INL Plot
0.3
TA = 25 C VDD = 5V
0.6
1.0 TA = 25 C VDD = 5V 0.5
TA = 25 C VDD = 5V
0.2
DNL ERROR (LSB) DNL ERROR (LSB)
0.4
DNL ERROR (LSB)
0.1
0.2
0
0
0
-0.1
-0.2 -0.4 -0.6 0
-0.5 -0.2
-0.3
0
50
100 150 CODE
200
250
200
400 600 CODE
800
1000
-1.0 0
1000
2000 CODE
3000
4000
TPC 4. AD5306 Typical DNL Plot
TPC 5. AD5316 Typical DNL Plot
TPC 6. AD5326 Typical DNL Plot
0.50 TA = 25 C VDD = 5V 0.25
0.5 0.4 0.3 VDD = 5V VREF = 3V MAX INL
ERROR (% FSR)
1.0
VDD = 5V VREF = 2V OFFSET ERROR
0.5
ERROR (LSB)
ERROR (LSB)
MAX INL
MAX DNL
0.2 0.1 0 -0.1 -0.2 MIN DNL MAX DNL
0
MIN DNL
0
GAIN ERROR
-0.25
-0.5
MIN INL
-0.3
MIN INL
-0.4
4 5
-0.50
0
1
2 3 VREF (V)
-0.5
-1.0
40 0 40 80 120 TEMPERATURE ( C)
40
0
40
80
120
TEMPERATURE ( C)
TPC 7. AD5306 INL and DNL Error vs. VREF
TPC 8. AD5306 INL and DNL Error vs. Temperature
TPC 9. AD5306 Offset Error and Gain Error vs. Temperature
REV. C
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AD5306/AD5316/AD5326
0.2 0.1 0 TA = 25 C VREF = 2V
5 5V SOURCE 3V SOURCE
VOUT (V)
600 500 TA = 25 C VDD = 5V VREF = 2V
4
GAIN ERROR
ERROR (% FSR)
400
IDD ( A)
-0.1 -0.2 -0.3 -0.4 -0.5 -0.6 OFFSET ERROR
3
300
2
200
1 3V SINK
5V SINK
100 0
0
1
2
3 VDD (V)
4
5
6
0
0
1 3 4 2 5 SINK/SOURCE CURRENT (mA)
6
ZERO SCALE CODE
FULL SCALE
TPC 10. Offset Error and Gain Error vs. VDD
TPC 11. VOUT vs. Source and Sink Current Capability
TPC 12. Supply Current vs. DAC Code
600 -40 C +25 C 500
0.5
650 TA = 25 C 600 DECREASING INCREASING
0.4
400 +105 C
IDD ( A)
-40 C
IDD ( A)
300
IDD ( A)
0.3
550
VDD = 5V
200
0.2
+25 C
500 DECREASING INCREASING 450 VDD = 3V
100 0 2.5
0.1
+105 C
3.0
3.5
4.0 VDD (V)
4.5
5.0
5.5
0 2.5
400
3.0 3.5 4.0 VDD (V) 4.5 5.0 5.5
0
1
2 3 VLOGIC (V)
4
5
TPC 13. Supply Current vs. Supply Voltage
TPC 14. Power-Down Current vs. Supply Voltage
TPC 15. Supply Current vs. Logic Input Voltage for SDA and SCL Voltage Increasing and Decreasing
CH1
TA = 25 C VDD = 5V VREF = 5V VOUTA
CH1
TA = 25 C VDD = 5V VREF = 2V VDD
CH1
TA = 25 C VDD = 5V VREF = 2V VOUTA
CH2
SCL
CH2
CH2 VOUTA
PD
CH1 1V, CH2 5V, TIME BASE = 1 s/DIV
CH1 2.00V, CH2 200mV, TIME BASE = 200 s/DIV
CH1 500mV, CH2 5.00V, TIME BASE = 1 s/DIV
TPC 16. Half-Scale Settling (1/4 to 3/4 Scale Code Change)
TPC 17. Power-On Reset to 0 V
TPC 18. Exiting Power-Down to Midscale
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2.50
VDD = 3V
10 0 -10
FREQUENCY
VDD = 5V
2.49
VOUT (V)
-20
dB
-30 2.48 -40 -50 2.47 -60 10
350
400
450 500 IDD ( A)
550
600
1 s/DIV
100
1k 10k 100k FREQUENCY (Hz)
1M
10M
TPC 19. IDD Histogram with VDD = 3 V and VDD = 5 V
TPC 20. AD5326 Major-Code Transition Glitch Energy
TPC 21. Multiplying Bandwidth (Small-Signal Frequency Response)
0.02 VDD = 5V TA = 25 C
FULL-SCALE ERROR (V)
0.01
0
-0.01
-0.02
0
1
2
3 VREF (V)
4
5
6
1mV/DIV
150ns/DIV
TPC 23. DAC-to-DAC Crosstalk
TPC 22. Full-Scale Error vs. VREF
FUNCTIONAL DESCRIPTION
where: D = decimal equivalent of the binary code that is loaded to the DAC register: 0-255 for AD5306 (8 bits) 0-1023 for AD5316 (10 bits) 0-4095 for AD5326 (12 bits) N = DAC resolution
VREF A
The AD5306/AD5316/AD5326 are quad resistor-string DACs fabricated on a CMOS process with resolutions of 8, 10, and 12 bits, respectively. Each contains four output buffer amplifiers and is written to via a 2-wire serial interface. They operate from single supplies of 2.5 V to 5.5 V, and the output buffer amplifiers provide rail-to-rail output swing with a slew rate of 0.7 V/ms. Each DAC is provided with a separate reference input, which may be buffered to draw virtually no current from the reference source, or unbuffered to give a reference input range from 0.25 V to VDD. The devices have a power-down mode in which all DACs may be turned off completely with a high impedance output.
Digital-to-Analog Section
BUF
REFERENCE BUFFER GAIN MODE (GAIN = 1 OR 2)
The architecture of one DAC channel consists of a resistor-string DAC followed by an output buffer amplifier. The voltage at the VREF pin provides the reference voltage for the corresponding DAC. Figure 4 shows a block diagram of the DAC architecture. Since the input coding to the DAC is straight binary, the ideal output voltage is given by
INPUT REGISTER
DAC REGISTER
RESISTOR STRING OUTPUT BUFFER AMPLIFIER
VOUTA
VOUT =
VREF D 2N
Figure 4. Single DAC Channel Architecture
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AD5306/AD5316/AD5326
Resistor String POWER-ON RESET
The resistor string section is shown in Figure 5. It is simply a string of resistors, each of value R. The digital code loaded to the DAC register determines at which node on the string the voltage is tapped off to be fed into the output amplifier. The voltage is tapped off by closing one of the switches connecting the string to the amplifier. Because it is a string of resistors, it is guaranteed monotonic.
DAC Reference Inputs
The AD5306/AD5316/AD5326 are provided with a power-on reset function so that they power up in a defined state. The power-on state is Normal operation Reference inputs unbuffered 0 V to VREF output range Output voltage set to 0 V
There is a reference pin for each of the four DACs. The reference inputs are buffered but can also be individually configured as unbuffered. The advantage with the buffered input is the high impedance it presents to the voltage source driving it. However, if the unbuffered mode is used, the user can have a reference voltage as low as 0.25 V and as high as VDD since there is no restriction due to headroom and footroom of the reference amplifier.
R R R TO OUTPUT AMPLIFIER
Both input and DAC registers are filled with zeros and remain so until a valid write sequence is made to the device. This is particularly useful in applications where it is important to know the state of the DAC outputs while the device is powering up.
SERIAL INTERFACE
The AD5306/AD5316/AD5326 are controlled via an I2C compatible serial bus. These devices are connected to this bus as slave devices (i.e., no clock is generated by the AD5306/AD5316/AD5326 DACs). This interface is SMBus compatible at VDD < 3.6 V. The AD5306/AD5316/AD5326 has a 7-bit slave address. The 5 MSB are 00011 and the 2 LSB are determined by the state of the A0 and A1 pins. The facility to make hardwired changes to A0 and A1 allows the user to have up to four of these devices on one bus. The 2-wire serial bus protocol operates as follows: 1. The master initiates data transfer by establishing a START condition, which is when a high-to-low transition on the SDA line occurs while SCL is high. The following byte is the address byte, which consists of the 7-bit slave address followed by an R/W bit (this bit determines whether data will be read from or written to the slave device). The slave whose address corresponds to the transmitted address responds by pulling SDA low during the ninth clock pulse (this is termed the acknowledge bit). At this stage, all other devices on the bus remain idle while the selected device waits for data to be written to or read from its shift register. 2. Data is transmitted over the serial bus in sequences of nine clock pulses (eight data bits followed by an acknowledge bit). The transitions on the SDA line must occur during the low period of SCL and remain stable during the high period of SCL. 3. When all data bits have been read or written to, a STOP condition is established. In write mode, the master will pull the SDA line high during the 10th clock pulse to establish a STOP condition. In read mode, the master will issue a No Acknowledge for the ninth clock pulse (i.e., the SDA line remains high). The master will then bring the SDA line low before the 10th clock pulse and then high during the 10th clock pulse to establish a STOP condition.
R R
Figure 5. Resistor String
If there is a buffered reference in the circuit (e.g., REF192), there is no need to use the on-chip buffers of the AD5306/ AD5316/AD5326. In unbuffered mode, the input impedance is still large at typically 180 kW per reference input for 0 V to VREF mode and 90 kW for 0 V to 2 VREF mode. The buffered/unbuffered option is controlled by the BUF bit in the control byte. The BUF bit setting applies to whichever DAC is selected in the pointer byte.
Output Amplifier
The output buffer amplifier is capable of generating output voltages to within 1 mV of either rail. Its actual range depends on the value of VREF, GAIN, offset error, and gain error. If a gain of 1 is selected (GAIN = 0), the output range is 0.001 V to VREF. If a gain of 2 is selected (GAIN = 1), the output range is 0.001 V to 2 VREF. Because of clamping, however, the maximum output is limited to VDD - 0.001 V. The output amplifier is capable of driving a load of 2 kW to GND or VDD, in parallel with 500 pF to GND or VDD. The source and sink capabilities of the output amplifier can be seen in the plot in TPC 11. The slew rate is 0.7 V/ms with a half-scale settling time to 0.5 LSB (at eight bits) of 6 ms.
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AD5306/AD5316/AD5326
Read/Write Sequence Input Shift Register
In the case of the AD5306/AD5316/AD5326, all write access sequences and most read sequences begin with the device address (with R/W = 0) followed by the pointer byte. This pointer byte specifies the data format and determines which DAC is being accessed in the subsequent read/write operation. See Figure 6. In a write operation, the data follows immediately. In a read operation, the address is resent with R/W = 1 and the data is then read back. However, it is also possible to perform a read operation by sending only the address with R/W = 1. The previously loaded pointer settings are then used for the readback operation.
MSB X X LEFT = 0 DOUBLE = 0 DACD LSB DACC DACB DACA
The input shift register is 16 bits wide. Data is loaded into the device as two data bytes on the serial data line, SDA, under the control of the serial clock input, SCL. The timing diagram for this operation is shown in Figure 1. The two data bytes consist of four control bits followed by 8, 10, or 12 bits of DAC data, depending on the device type. The first bits loaded are the control bits: GAIN, BUF, CLR, and PD. The remaining bits are left-justified DAC data bits, starting with the MSB. See Figure 7. GAIN 0: Output range for that DAC set at 0 V to VREF. 1: Output range for that DAC set at 0 V to 2 VREF. BUF CLR 0: Reference input for that DAC is unbuffered. 1: Reference input for that DAC is buffered. 0: All DAC registers and input registers are filled with zeros on completion of the write sequence. 1: Normal operation. 0: On completion of the write sequence, all four DACs go into power-down mode. The DAC outputs enter a high impedance state. 1: Normal operation.
Figure 6. Pointer Byte
Pointer Byte Bits
The following is an explanation of the individual bits that make up the pointer byte. X LEFT Don't care bits. 0: Data written to the device and read from the device is left-justified.
PD
Default Readback Conditions
DOUBLE 0: Data write and readback are done as 2-byte write/read sequences. DACD DACC DACB DACA 1: The following data bytes are for DAC D. 1: The following data bytes are for DAC C. 1: The following data bytes are for DAC B. 1: The following data bytes are for DAC A.
All pointer byte bits power up to 0. Therefore, if the user initiates a readback without first writing to the pointer byte, no single DAC channel has been specified. In this case, the default readback bits are all 0 except for the CLR bit and the PD bit, which are 1.
Multiple-DAC Write Sequence
Because there are individual bits in the pointer byte for each DAC, it is possible to write the same data and control bits to 2, 3, or 4 DACs simultaneously by setting the relevant bits to 1.
Multiple-DAC Readback Sequence
If the user attempts to read back data from more than one DAC at a time, the part will read back the power-on condition of GAIN, BUF, and data bits (all 0), and the current state of CLR and PD.
DATA BYTES (WRITE AND READBACK)
MSB GAIN MSB GAIN MSB GAIN BUF CLR BUF CLR BUF MOST SIGNIFICANT DATA BYTE 8-BIT AD5306 CLR PD D7 D6 D5 LSB D4 LSB D8 D7 D6 LSB D10 D9 D8 MSB D3 MSB D5 MSB D7 D6 D5 D4 D3 D2 LEAST SIGNIFICANT DATA BYTE 8-BIT AD5306 D1 D0 X X X LSB X LSB D0 X X LSB D2 D1 D0
10-BIT AD5316 PD D9
10-BIT AD5316 D2 D1
12-BIT AD5326 PD D11
12-BIT AD5326 D4 D3
Figure 7. Data Formats for Write and Readback
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WRITE OPERATION READ OPERATION
When writing to the AD5306/AD5316/AD5326 DACs, the user must begin with an address byte (R/W = 0), after which the DAC will acknowledge that it is prepared to receive data by pulling SDA low. This address byte is followed by the pointer byte, which is also acknowledged by the DAC. Two bytes of data are then written to the DAC, as shown in Figure 8. A STOP condition follows.
When reading data back from the AD5306/AD5316/AD5326 DACs, the user begins with an address byte (R/W = 0), after which the DAC will acknowledge that it is prepared to receive data by pulling SDA low. This address byte is usually followed by the pointer byte, which is also acknowledged by the DAC. Following this, there is a repeated start condition by the master and the address is resent with R/W = 1. This is acknowledged by the DAC indicating that it is prepared to transmit data. Two bytes of data are then read from the DAC, as shown in Figure 9. A STOP condition follows.
SCL
SDA START COND BY MASTER
0
0
0
1
1
A1
A0
R/W ACK BY AD53x6
X MSB
X POINTER BYTE
LSB ACK BY AD53x6
ADDRESS BYTE
SCL
SDA
MSB MOST SIGNIFICANT DATA BYTE
LSB ACK BY AD53x6
MSB LEAST SIGNIFICANT DATA BYTE
LSB ACK BY AD53x6 STOP COND BY MASTER
Figure 8. Write Sequence
SCL
SDA START COND BY MASTER SCL
0
0
0
1
1
A1
A0
R/W ACK BY AD53x6
X MSB
X
LSB ACK BY AD53x6
ADDRESS BYTE
POINTER BYTE
SDA
0 REPEATED START COND BY MASTER
0
0
1
1
A1
A0
R/W ACK BY AD53x6
MSB
LSB ACK BY MASTER
ADDRESS BYTE
MOST SIGNIFICANT DATA BYTE
SCL
SDA
MSB LEAST SIGNIFICANT DATA BYTE
LSB NO ACK BY MASTER STOP COND BY MASTER
NOTE: DATA BYTES ARE THE SAME AS THOSE IN THE WRITE SEQUENCE, EXCEPT THAT DON'T CARES ARE READ BACK AS 0s.
Figure 9. Readback Sequence
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AD5306/AD5316/AD5326
However, if the master sends an ACK and continues clocking SCL (no STOP is sent), the DAC will retransmit the same two bytes of data on SDA. This allows continuous readback of data from the selected DAC register. Alternatively, the user may send a START followed by the address with R/W = 1. In this case, the previously loaded pointer settings are used and readback of data can commence immediately.
DOUBLE-BUFFERED INTERFACE
The AD5306/AD5316/AD5326 DACs have double-buffered interfaces consisting of two banks of registers: input registers and DAC registers. The input registers are connected directly to the input shift register and the digital code is transferred to the relevant input register on completion of a valid write sequence. The DAC registers contain the digital code used by the resistor strings. Access to the DAC registers is controlled by the LDAC pin. When LDAC is high, the DAC registers are latched and the input registers may change state without affecting the contents of the DAC registers. When LDAC is brought low, however, the DAC registers become transparent and the contents of the input registers are transferred to them. Double-buffering is useful if the user requires simultaneous updating of all DAC outputs. The user may write to each of the input registers individually and then, by pulsing the LDAC input low, all outputs will update simultaneously. These parts contain an extra feature whereby a DAC register is not updated unless its input register has been updated since the last time that LDAC was low. Normally, when LDAC is low, the DAC registers are filled with the contents of the input registers. In the case of the AD5306/AD5316/AD5326, the part will update the DAC register only if the input register has been changed since the last time the DAC register was updated, thereby removing unnecessary digital crosstalk.
Load DAC Input LDAC
When the PD pin is high and the PD bit is set to 1, all DACs work normally with a typical power consumption of 500 mA at 5 V (400 mA at 3 V). In power-down mode, however, the supply current falls to 300 nA at 5 V (90 nA at 3 V) when all DACs are powered down. Not only does the supply current drop, but each output stage is also internally switched from the output of its amplifier, making it open-circuit. This has the advantage that the outputs are three-state while the part is in power-down mode and provides a defined input condition for whatever is connected to the output of the DAC amplifiers. The output stage is illustrated in Figure 10.
AMPLIFIER RESISTOR STRING DAC VOUT
POWER-DOWN CIRCUITRY
Figure 10. Output Stage during Power-Down
The bias generator, the output amplifiers, the resistor strings, and all other associated linear circuitry are shut down when the power-down mode is activated. However, the contents of the registers are unaffected when in power-down. In fact, it is possible to load new data to the input registers and DAC registers during power-down. The DAC outputs will update as soon as the PD pin goes high or the PD bit is reset to 1. The time to exit power-down is typically 2.5 ms for VDD = 5 V and 5 ms when VDD = 3 V. This is the time from the rising edge of the eighth SCL pulse or from the rising edge of PD to when the output voltage deviates from its power-down voltage. See TPC 18.
APPLICATIONS Typical Application Circuit
LDAC transfers data from the input registers to the DAC registers (and, therefore, updates the outputs). Use of the LDAC function enables double-buffering of the DAC data, GAIN, and BUF. There are two LDAC modes: Synchronous Mode: In this mode, the DAC registers are updated after new data is read in on the rising edge of the eighth SCL pulse. LDAC can be tied permanently low or pulsed as in Figure 2. Asynchronous Mode: In this mode, the outputs are not updated at the same time that the input registers are written to. When LDAC goes low, the DAC registers are updated with the contents of the input registers.
POWER-DOWN MODE
The AD5306/AD5316/AD5326 can be used with a wide range of reference voltages where the devices offer full, one-quadrant multiplying capability over a reference range of 0 V to VDD. More typically, these devices are used with a fixed, precision reference voltage. Suitable references for 5 V operation are the AD780 and REF192 (2.5 V references). For 2.5 V operation, a suitable external reference would be the AD589, a 1.23 V band gap reference. Figure 11 shows a typical setup for the AD5306/ AD5316/AD5326 when using an external reference. Note that A0 and A1 can be high or low.
VDD = 2.5V TO 5.5V 0.1 F 10 F
AD5306/AD5316/ AD5326
VIN VOUT EXT REF AD780/REF192 WITH VDD = 5V OR AD589 WITH VDD = 2.5V SERIAL INTERFACE 1F VREFA VREFB VREFC VREFD SCL SDA A0 GND A1 VOUTA VOUTB VOUTC VOUTD
The AD5306/AD5316/AD5326 have very low power consumption, dissipating typically 1.2 mW with a 3 V supply and 2.5 mW with a 5 V supply. Power consumption can be further reduced when the DACs are not in use by putting them into power-down mode, which is selected by setting the PD pin low or by setting Bit 12 (PD) of the data word to 0.
Figure 11. AD5306/AD5316/AD5326 Using a 2.5 V External Reference
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Driving VDD from the Reference Voltage Multiple Devices on One Bus
If an output range of 0 V to VDD is required when the reference inputs are configured as unbuffered, the simplest solution is to connect the reference inputs to VDD. As this supply may be noisy and not very accurate, the AD5306/AD5316/AD5326 may be powered from the reference voltage; for example, using a 5 V reference such as the REF195. The REF195 will output a steady supply voltage for the AD5306/AD5316/AD5326. The typical current required from the REF195 is 500 mA supply current and approximately 112 mA to supply the reference inputs (if unbuffered). This is with no load on the DAC outputs. When the DAC outputs are loaded, the REF195 also needs to supply the current to the loads. The total current required (with a 10 kW load on each output) is 612 mA + 4(5V / 10 kW) = 2.6 mA The load regulation of the REF195 is typically 2 ppm/mA, which results in an error of 5.2 ppm (26 mV) for the 2.6 mA current drawn from it. This corresponds to a 0.0013 LSB error at eight bits and 0.021 LSB error at 12 bits.
Bipolar Operation Using the AD5306/AD5316/AD5326
Figure 13 shows four AD5306 devices on the same serial bus. Each has a different slave address since the states of the A0 and A1 pins are different. This allows each of 16 DACs to be written to or read from independently.
VDD PULL-UP RESISTORS A1 VDD A1
AD5306
A0 SDA SCL A0
AD5306
SDA SCL
MASTER SDA A1 A0 SCL VDD A1 SDA A0 SCL
AD5306
AD5306
Figure 13. Multiple AD5306 Devices on One Bus
AD5306/AD5316/AD5326 as a Digitally Programmable Window Detector
The AD5306/AD5316/AD5326 have been designed for singlesupply operation, but a bipolar output range is also possible using the circuit in Figure 12. This circuit will give an output voltage range of 5 V. Rail-to-rail operation at the amplifier output is achievable using an AD820 or an OP295 as the output amplifier.
R2 10k +5V 6V TO 12V 0.1 F 10 F VDD VIN AD1585 VOUT GND 1F VOUTA AD820/ OP295 -5V R1 10k 5V
A digitally programmable upper/lower limit detector using two of the DACs in the AD5306/AD5316/AD5326 is shown in Figure 14. The upper and lower limits for the test are loaded to DACs A and B, which, in turn, set the limits on the CMP04. If the signal at the VIN input is not within the programmed window, an LED will indicate the fail condition. Similarly, DACs C and D can be used for window detection on a second VIN signal.
5V 0.1 F 10 F VIN VDD VOUTA 1/2 CMP04 PASS/FAIL 1k FAIL 1k PASS
5V
VREF
VREFA VREFB
AD5306/AD5316/ AD5326
VREFA VREFB VREFC VREFD A1 A0 GND VOUTB VOUTC VOUTD
1/2 AD5306/AD5316/ AD5326*
DIN SCL SDA SCL GND VOUTB
1/6 74HC05
*ADDITIONAL PINS OMITTED FOR CLARITY
SCL SDA
Figure 14. Window Detection
Coarse and Fine Adjustment Using the AD5306/AD5316/ AD5326
2-WIRE SERIAL INTERFACE
Figure 12. Bipolar Operation with the AD5306/ AD5316/AD5326
The output voltage for any input code can be calculated as follows:
E REFIN D 2N ( R1 + R2) VOUT = I I R1 - REFIN ( R2 / R1) I
(
)
where: D is the decimal equivalent of the code loaded to the DAC. N is the DAC resolution. REFIN is the reference voltage input. with: REFIN = 5 V, R1 = R2 = 10 kW:
VOUT = 10 D / 2N - 5V
Two of the DACs in the AD5306/AD5316/AD5326 can be paired together to form a coarse and fine adjustment function, as shown in Figure 15. DAC A is used to provide the coarse adjustment while DAC B provides the fine adjustment. Varying the ratio of R1 and R2 will change the relative effect of the coarse and fine adjustments. With the resistor values and external reference shown, the output amplifier has unity gain for the DAC A output, so the output range is 0 V to 2.5 V - 1 LSB. For DAC B, the amplifier has a gain of 7.6 10-3, giving DAC B a range equal to 19 mV. Similarly, DACs C and D can be paired together for coarse and fine adjustment. The circuit is shown with a 2.5 V reference, but reference voltages up to VDD may be used. The op amps indicated will allow a rail-to-rail output swing.
(
)
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AD5306/AD5316/AD5326
VDD = 5V R3 51.2k R4 390 5V 0.1 F 10 F VDD V OUTA VIN EXT REF VOUT GND 0.1 F VREFA VREFB VOUTB R2 51.2k R1 390 AD820/ OP295
VOUT
should be established as close as possible to the device. The AD5306/AD5316/AD5326 should have ample supply bypassing of 10 mF in parallel with 0.1 mF on the supply located as close to the package as possible, ideally right up against the device. The 10 mF capacitors are the tantalum bead type. The 0.1 mF capacitor should have low effective series resistance (ESR) and effective series inductance (ESI), like the common ceramic types that provide a low impedance path to ground at high frequencies, to handle transient currents due to internal logic switching. The power supply lines of the AD5306/AD5316/AD5326 should use as large a trace as possible to provide low impedance paths and reduce the effects of glitches on the power supply line. Fast switching signals such as clocks should be shielded with digital ground to avoid radiating noise to other parts of the board, and should never be run near the reference inputs. A ground line routed between the SDA and SCL lines will help reduce crosstalk between them (not required on a multilayer board as there will be a separate ground plane, but separating the lines will help). Avoid crossover of digital and analog signals. Traces on opposite sides of the board should run at right angles to each other. This reduces the effects of feedthrough through the board. A microstrip technique is by far the best, but is not always possible with a double-sided board. In this technique, the component side of the board is dedicated to ground plane while signal traces are placed on the solder side.
AD780/REF192 WITH VDD = 5V
1/2 AD5306/AD5316/ AD5326
GND
Figure 15. Coarse/Fine Adjustment
POWER SUPPLY DECOUPLING
In any circuit where accuracy is important, careful consideration of the power supply and ground return layout helps to ensure the rated performance. The printed circuit board on which the AD5306/AD5316/AD5326 is mounted should be designed so that the analog and digital sections are separated and confined to certain areas of the board. If the AD5306/AD5316/AD5326 is in a system where multiple devices require an AGND-to-DGND connection, the connection should be made at one point only. The star ground point
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Table I. Overview of AD53xx Serial Devices
Part No. SINGLES AD5300 AD5310 AD5320 AD5301 AD5311 AD5321 DUALS AD5302 AD5312 AD5322 AD5303 AD5313 AD5323 QUADS AD5304 AD5314 AD5324 AD5305 AD5315 AD5325 AD5306 AD5316 AD5326 AD5307 AD5317 AD5327 OCTALS AD5308 AD5318 AD5328
Resolution
No. of DACs
DNL 0.25 0.5 1.0 0.25 0.5 1.0 0.25 0.5 1.0 0.25 0.5 1.0 0.25 0.5 1.0 0.25 0.5 1.0 0.25 0.5 1.0 0.25 0.5 1.0 0.25 0.5 1.0
Interface SPI(R) SPI SPI 2-Wire 2-Wire 2-Wire
Settling Time ( s)
Package
Pins
8 10 12 8 10 12
1 1 1 1 1 1
4 6 8 6 7 8
SOT-23, MSOP SOT-23, MSOP SOT-23, MSOP SOT-23, MSOP SOT-23, MSOP SOT-23, MSOP
6, 8 6, 8 6, 8 6, 8 6, 8 6, 8
8 10 12 8 10 12
2 2 2 2 2 2
SPI SPI SPI SPI SPI SPI
6 7 8 6 7 8
MSOP MSOP MSOP TSSOP TSSOP TSSOP
8 8 8 16 16 16
8 10 12 8 10 12 8 10 12 8 10 12
4 4 4 4 4 4 4 4 4 4 4 4
SPI SPI SPI 2-Wire 2-Wire 2-Wire 2-Wire 2-Wire 2-Wire SPI SPI SPI
6 7 8 6 7 8 6 7 8 6 7 8
MSOP MSOP MSOP MSOP MSOP MSOP TSSOP TSSOP TSSOP TSSOP TSSOP TSSOP
10 10 10 10 10 10 16 16 16 16 16 16
8 10 12
8 8 8
SPI SPI SPI
6 7 8
TSSOP TSSOP TSSOP
16 16 16
Visit www.analog.com/support/standard_linear/selection_guides/AD53xx.html for more information.
Table II. Overview of AD53xx Parallel Devices
Part No. SINGLES AD5330 AD5331 AD5340 AD5341 DUALS AD5332 AD5333 AD5342 AD5343 QUADS AD5334 AD5335 AD5336 AD5344
Resolution 8 10 12 12 8 10 12 12 8 10 10 12
DNL 0.25 0.5 1.0 1.0 0.25 0.5 1.0 1.0 0.25 0.5 0.5 1.0
VREF Pins 1 1 1 1 2 2 2 1 2 2 4 4
Settling Time ( s) 6 7 8 8 6 7 8 8 6 7 7 8
Additional Pin Functions BUF GAIN HBEN CLR
Package TSSOP TSSOP TSSOP TSSOP TSSOP TSSOP TSSOP TSSOP TSSOP TSSOP TSSOP TSSOP
Pins 20 20 24 20 20 24 28 20 24 24 28 28

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OUTLINE DIMENSIONS 16-Lead Thin Shrink Small Outline Package [TSSOP] (RU-16)
Dimensions shown in millimeters
5.10 5.00 4.90
16
9
4.50 4.40 4.30
1 8
6.40 BSC
PIN 1 1.20 MAX 0.20 0.09 0.65 BSC 0.30 0.19 COPLANARITY 0.10 SEATING PLANE 8 0 0.75 0.60 0.45
0.15 0.05
COMPLIANT TO JEDEC STANDARDS MO-153AB
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AD5306/AD5316/AD5326 Revision History
Location 8/03--Data Sheet changed from REV. B to REV. C. Page
Added A Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Universal Changes to SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Changes to ABSOLUTE MAXIMUM RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Edits to ORDERING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Changes to TPC 21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Added OCTALS section to Table I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Updated OUTLINE DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4/01--Data sheet changed from REV. A to REV. B.
C02066-0-8/03(C)
Changes to FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Edit to Figure 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Edits to RIGHT/LEFT section of Pointer Byte Bits section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Edits to Input Shift Register section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Edits to Figure 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Edits to Figure 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Edits to Figure 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Edit to Figure 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Purchase of licensed I 2C components of Analog Devices or one of its sublicensed Associated Companies conveys a license for the purchaser under the Philips I 2C Patent Rights to use these components in an I 2C system, provided that the system conforms to the I 2C Standard Specification as defined by Philips.
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REV. C
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