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Quad-Channel Isolator with Integrated DC-to-DC Converter ADuM5400
FEATURES
isoPower integrated, isolated dc-to-dc converter Regulated 5 V output 500 mW output power Quad dc-to-25 Mbps (NRZ) signal isolation channels Schmitt trigger inputs 16-lead SOIC package with >8 mm creepage High temperature operation: 105C maximum High common-mode transient immunity: >25 kV/s Safety and regulatory approvals UL recognition 2500 V rms for 1 minute per UL 1577 CSA Component Acceptance Notice #5A (pending) VDE certificate of conformity (pending) DIN V VDE V 0884-10 (VDE V 0884-10):2006-12 VIORM = 560 V peak
GENERAL DESCRIPTION
The ADuM54001 device is a quad-channel digital isolator with isoPower(R), an integrated, isolated dc-to-dc converter. Based on the Analog Devices, Inc., iCoupler(R) technology, the dc-to-dc converter provides up to 500 mW of regulated, isolated power with 5.0 V input and 5.0 V output voltages. This architecture eliminates the need for a separate, isolated dc-to-dc converter in low power, isolated designs. The iCoupler chip scale transformer technology is used to isolate the logic signals and the magnetic components of the dc-to-dc converter. The result is a small form factor, total isolation solution. The ADuM5400 isolator provides four independent isolation channels in two speed grades (see the Ordering Guide for more information). isoPower uses high frequency switching elements to transfer power through its transformer. Special care must be taken during printed circuit board (PCB) layout to meet emissions standards. Refer to the AN-0971 application note for details on board layout recommendations.
APPLICATIONS
RS-232/RS-422/RS-485 transceivers Industrial field bus isolation Power supply start-up bias and gate drives Isolated sensor interfaces Industrial PLCs
FUNCTIONAL BLOCK DIAGRAM
VDD1 1 GND1 2 VIA 3 VIB 4 VIC 5 VID 6 VDDL 7 GND1 8 4-CHANNEL iCOUPLER CORE OSC RECT REG
16 VISO 15 GNDISO 14 VOA 13 VOB
ADuM5400
12 VOC 11 VOD 10 VISO 9
GNDISO
Figure 1.
1
Protected by U.S. Patents 5,952,849; 6,873,065; 6,903,578; and 7,075,329; other patents pending.
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 (c)2008 Analog Devices, Inc. All rights reserved.
07509-001
ADuM5400 TABLE OF CONTENTS
Features .............................................................................................. 1 Applications ....................................................................................... 1 General Description ......................................................................... 1 Functional Block Diagram .............................................................. 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Electrical Characteristics ............................................................. 3 Package Characteristics ............................................................... 5 Regulatory Information ............................................................... 5 Insulation and Safety Related Specifications ............................ 5 DIN V VDE V 0884-10 (VDE V 0884-10) Insulation Characteristics .............................................................................. 6 Recommended Operating Conditions ...................................... 6 Absolute Maximum Ratings............................................................ 7 ESD Caution .................................................................................. 7 Pin Configuration and Function Descriptions..............................8 Typical Performance Characteristics ..............................................9 Terminology .................................................................................... 11 Applications Information .............................................................. 12 PCB Layout ................................................................................. 12 EMI Considerations ................................................................... 12 Propagation Delay Parameters ................................................. 13 DC Correctness and Magnetic Field Immunity ..................... 13 Power Consumption .................................................................. 14 Power Considerations ................................................................ 14 Thermal Analysis ....................................................................... 15 Insulation Lifetime ..................................................................... 15 Outline Dimensions ....................................................................... 16 Ordering Guide .......................................................................... 16
REVISION HISTORY
10/08--Revision 0: Initial Version
Rev. 0 | Page 2 of 16
ADuM5400 SPECIFICATIONS
ELECTRICAL CHARACTERISTICS
4.5 V VDD1 5.5 V; each voltage is relative to its respective ground. All minimum/maximum specifications apply over the entire recommended operating range, unless otherwise noted. All typical specifications are at TA = 25C, VDD1 = 5.0 V, VISO = 5.0 V. Table 1.
Parameter DC-TO-DC CONVERTER POWER SUPPLY Setpoint Line Regulation Load Regulation Output Ripple Output Noise Switching Frequency Pulse-Width Modulation Frequency DC to 2 Mbps Data Rate 1 Maximum Output Supply Current 2 Efficiency at Maximum Output Supply Current 3 IDD1 Supply Current, No VISO Load IDD1 Supply Current, Full VISO Load 25 Mbps Data Rate (CRWZ Grade Only) IDD1 Supply Current, No VISO Load Available VISO Supply Current 4 Undervoltage Lockout, VDD1, VDDL, and VISO Supplies 5 Positive Going Threshold Negative Going Threshold Hysteresis iCoupler DATA CHANNELS I/O Input Currents Logic High Input Threshold Logic Low Input Threshold Logic High Output Voltages Symbol VISO VISO(LINE) VISO(LOAD) VISO(RIP) VISO(N) fOSC fPWM IISO(MAX) 100 34 IDD1(Q) IDD1(MAX) 19 290 30 Min 4.7 Typ 5.0 1 1 75 200 180 625 Max 5.4 5 Unit V mV/V % mV p-p mV p-p MHz kHz mA % mA mA Test Conditions/Comments IISO = 0 mA IISO = 50 mA, VDD1 = 4.5 V to 5.5 V IISO = 10 mA to 90 mA 20 MHz bandwidth, CBO = 0.1 F||10 F, IISO = 90 mA CBO = 0.1 F||10 F, IISO = 90 mA
VISO > 4.5 V, dc to 1 MHz logic signal frequency IISO = 100 mA, dc to 1 MHz logic signal frequency IISO = 0 mA, dc to 1 MHz logic signal frequency CL = 0 pF, dc to 1 MHz logic signal frequency, VDD = 4.5 V, IISO = 100 mA IISO = 0 mA, CL = 15 pF, 12.5 MHz logic signal frequency CL = 15 pF, 12.5 MHz logic signal frequency
IDD1(D) IISO(LOAD)
64 89
mA mA
VUV+ VUV- VUVH IIA, IIB, IIC, IID VIH VIL VOAH, VOBH, VOCH, VODH VOAL, VOBL, VOCL, VODL -20 0.7 x VIDD1 VISO - 0.3 VISO - 0.5
2.7 2.4 0.3 +0.01 +20 0.3 x VIDD1 5.0 4.8 0.0 0.0
V V V A V V V V V V
IOx = -20 A, VIx = VIxH IOx = -4 mA, VIx = VIxH IOx = 20 A, VIx = VIxL IOx = 4 mA, VIx = VIxL
Logic Low Output Voltages
0.1 0.4
AC SPECIFICATIONS ADuM5400ARWZ Minimum Pulse Width 6 Maximum Data Rate Propagation Delay Pulse Width Distortion, |tPLH - tPHL| Propagation Delay Skew Channel-to-Channel Matching
PW 1 tPHL, tPLH PWD tPSK tPSKCD/tPSKOD 55
1000 100 40 50 50
ns Mbps ns ns ns ns
CL = 15 pF, CMOS signal levels CL = 15 pF, CMOS signal levels CL = 15 pF, CMOS signal levels CL = 15 pF, CMOS signal levels CL = 15 pF, CMOS signal levels CL = 15 pF, CMOS signal levels
Rev. 0 | Page 3 of 16
ADuM5400
Parameter ADuM5400CRWZ Minimum Pulse Width6 Maximum Data Rate Propagation Delay Pulse Width Distortion, |tPLH - tPHL| Change vs. Temperature Propagation Delay Skew Channel-to-Channel Matching, Codirectional Channels Channel-to-Channel Matching, Opposing Directional Channels For All Models Output Rise/Fall Time (10% to 90%) Common-Mode Transient Immunity at Logic High Output Common-Mode Transient Immunity at Logic Low Output Refresh Rate
1 2
Symbol PW
Min
Typ
Max 40
Unit ns Mbps ns ns ps/C ns ns ns
Test Conditions/Comments CL = 15 pF, CMOS signal levels CL = 15 pF, CMOS signal levels CL = 15 pF, CMOS signal levels CL = 15 pF, CMOS signal levels CL = 15 pF, CMOS signal levels CL = 15 pF, CMOS signal levels CL = 15 pF, CMOS signal levels CL = 15 pF, CMOS signal levels
25 tPHL, tPLH PWD tPSK tPSKCD tPSKOD 45 5 15 6 15 60 6
tR/tF |CMH| |CML| fr
25 25
2.5 35 35 1.0
ns kV/s kV/s Mbps
CL = 15 pF, CMOS signal levels VIx = VDD or VISO, VCM = 1000 V, transient magnitude = 800 V VIx = 0 V, VCM = 1000 V, transient magnitude = 800 V
The contributions of supply current values for all four channels are combined at identical data rates. The VISO supply current is available for external use when all data rates are below 2 Mbps. At data rates above 2 Mbps, the data I/O channels draw additional current proportional to the data rate. Additional supply current associated with an individual channel operating at a given data rate can be calculated as described in the Power Consumption section. The dynamic I/O channel load must be treated as an external load and included in the VISO power budget. 3 The power demands of the quiescent operation of the data channels cannot be separated from the power supply section. Efficiency includes the quiescent power consumed by the I/O channels as part of the internal power consumption. 4 This current is available for driving external loads at the VISO pin. All channels are simultaneously driven at a maximum data rate of 25 Mbps with full capacitive load representing the maximum dynamic load conditions. Refer to the Power Consumption section for calculation of available current at less than the maximum data rate. 5 Undervoltage lockout (UVLO) holds the outputs in a low state if the corresponding input or output power supply is below the referenced threshold. Hysteresis is built into the detection threshold to prevent oscillations and noise sensitivity. 6 The minimum pulse width is the shortest pulse width at which the specified pulse width distortion is guaranteed.
Rev. 0 | Page 4 of 16
ADuM5400
PACKAGE CHARACTERISTICS
Table 2.
Parameter Resistance (Input to Output) 1 Capacitance (Input to Output)1 Input Capacitance 2 IC Junction to Ambient Thermal Resistance
1 2
Symbol RI-O CI-O CI JA
Min
Typ 1012 2.2 4.0 45
Max
Unit pF pF C/W
Test Conditions f = 1 MHz Thermocouple located at center of package underside, test conducted on 4-layer board with thin traces 3
The device is considered a 2-terminal device: Pin 1 to Pin 8 are shorted together, and Pin 9 to Pin 16 are shorted together. Input capacitance is from any input data pin to ground. 3 See the Thermal Analysis section for thermal model definitions.
REGULATORY INFORMATION
The ADuM5400 is approved by the organizations listed in Table 3. Refer to Table 8 and to the Insulation Lifetime section for details regarding the recommended maximum working voltages for specific cross-isolation waveforms and insulation levels. Table 3.
UL Recognized under 1577 Component Recognition Program 1 Single Protection 2500 V RMS Isolation Voltage CSA (Pending) Approved under CSA Component Acceptance Notice #5A Reinforced insulation per CSA 60950-1-03 and IEC 60950-1, 400 V rms (566 V peak) maximum working voltage File 205078 VDE (Pending) Certified according to DIN V VDE V 0884-10 (VDE V 0884-10):2006-12 2 Reinforced insulation, 560 V peak
File E214100
1 2
File 2471900-4880-0001
In accordance with UL 1577, each ADuM5400 is proof-tested by applying an insulation test voltage of 3000 V rms for 1 sec (current leakage detection limit = 10 A). In accordance with DIN V VDE V 0884-10, each ADuM5400 is proof-tested by applying an insulation test voltage of 1050 V peak for 1 sec (partial discharge detection limit = 5 pC). The asterisk (*) marking branded on the component designates DIN V VDE V 0884-10 approval.
INSULATION AND SAFETY RELATED SPECIFICATIONS
Table 4.
Parameter Rated Dielectric Insulation Voltage Minimum External Air Gap (Clearance) Minimum External Tracking (Creepage) Minimum Internal Gap (Internal Clearance) Tracking Resistance (Comparative Tracking Index) Isolation Group Symbol L(I01) L(I02) Value 2500 >8.0 >8.0 0.017 min >175 IIIa Unit V rms mm mm mm V Test Conditions/Comments 1-minute duration Measured from input terminals to output terminals, shortest distance through air Measured from input terminals to output terminals, shortest distance path along body Distance through insulation DIN IEC 112/VDE 0303 Part 1 Material group (DIN VDE 0110, 1/89, Table 1)
CTI
Rev. 0 | Page 5 of 16
ADuM5400
DIN V VDE V 0884-10 (VDE V 0884-10) INSULATION CHARACTERISTICS
The ADuM5400 is suitable for reinforced electrical isolation only within the safety limit data. Maintenance of the safety data is ensured by protective circuits. The asterisk (*) marking on the package denotes DIN V VDE V 0884-10 approval. Table 5.
Description Installation Classification per DIN VDE 0110 For Rated Mains Voltage 150 V rms For Rated Mains Voltage 300 V rms For Rated Mains Voltage 400 V rms Climatic Classification Pollution Degree per DIN VDE 0110, Table 1 Maximum Working Insulation Voltage Input-to-Output Test Voltage, Method b1 Input-to-Output Test Voltage, Method a After Environmental Tests Subgroup 1 After Input and/or Safety Test Subgroup 2 and Subgroup 3 Highest Allowable Overvoltage Safety Limiting Values Case Temperature Side 1 Current, IDD1 Insulation Resistance at TS Conditions Symbol Characteristic I to IV I to III I to II 40/105/21 2 560 1050 Unit
VIORM x 1.875 = VPR, 100% production test, tm = 1 sec, partial discharge < 5 pC VIORM x 1.6 = VPR, tm = 60 sec, partial discharge < 5 pC VIORM x 1.2 = VPR, tm = 60 sec, partial discharge < 5 pC Transient overvoltage, tTR = 10 sec Maximum value allowed in the event of a failure (see Figure 2)
VIORM VPR VPR
V peak V peak
896 672 VTR 4000
V peak V peak V peak
VIO = 500 V
TS IS1 RS
150 555 >109
C mA
Thermal Derating Curve
600
SAFE OPERATING VDD1 CURRENT (mA)
500
400
300
200
100
0
0
50 100 150 AMBIENT TEMPERATURE (C)
200
Figure 2. Thermal Derating Curve, Dependence of Safety Limiting Values on Case Temperature, per DIN EN 60747-5-2
RECOMMENDED OPERATING CONDITIONS
Table 6.
Parameter Operating Temperature Range Supply Voltages1 Minimum Load2
1 2
Symbol TA VDD IISO(MIN)
Min -40 4.5 10
07509-003
Max +105 5.5
Unit C V mA
Each voltage is relative to its respective ground. If the external load is less than the specified value, the power supply PWM can generate excess switching noise, potentially causing data integrity issues.
Rev. 0 | Page 6 of 16
ADuM5400 ABSOLUTE MAXIMUM RATINGS
TA = 25C, unless otherwise noted. Table 7.
Parameter Storage Temperature (TST) Ambient Operating Temperature (TA) Supply Voltages (VDD1, VISO) 1 VISO Supply Current 2 -40C to +85C -40C to +105C Input Voltage (VIA, VIB, VIC, VID)1, 3 Output Voltage (VOA, VOB, VOC, VOD)1, 3 Average Output Current per Data Output Pin 4 Common-Mode Transients 5
1 2
Rating -55C to +150C -40C to +85C -0.5 V to +7.0 V 100 mA 60 mA -0.5 V to VDDI + 0.5 V -0.5 V to VISO + 0.5 V -10 mA to +10 mA -100 kV/s to +100 kV/s
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 indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
ESD CAUTION
Each voltage is relative to its respective ground. VISO provides current for dc and dynamic loads on the Side 2 I/O channels. This current must be included when determining the total VISO supply current. 3 VDD1 and VISO refer to the supply voltages on the input and output sides of a given channel, respectively. See the PCB Layout section. 4 See Figure 2 for maximum rated current values for various temperatures. 5 Refers to common-mode transients across the insulation barrier. Commonmode transients exceeding the absolute maximum ratings may cause latch-up or permanent damage.
Table 8. Maximum Continuous Working Voltage Supporting 50-Year Minimum Lifetime1
Parameter AC Voltage Bipolar Waveform Unipolar Waveform Basic Insulation Reinforced Insulation DC Voltage Basic Insulation Reinforced Insulation
1
Maximum 424 600 560 600 560
Unit V peak V peak V peak V peak V peak
Reference Standard 50-year minimum lifetime Maximum approved working voltage per IEC 60950-1 Maximum approved working voltage per IEC 60950-1 and VDE V 0884-10 Maximum approved working voltage per IEC 60950-1 Maximum approved working voltage per IEC 60950-1 and VDE V 0884-10
Refers to the continuous voltage magnitude imposed across the isolation barrier. See the Insulation Lifetime section for more information.
Rev. 0 | Page 7 of 16
ADuM5400 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
VDD1 1 GND1 2 VIA 3 VIB 4 VIC 5 VID 6 VDDL 7 GND1 8
16 15
VISO GNDISO VOA
ADuM5400
14
13 VOB TOP VIEW (Not to Scale) 12 VOC 11 10 9
VOD GNDISO
07509-004
VISO
Figure 3. Pin Configuration
Table 9. Pin Function Descriptions
Pin No. 1 2, 8 3 4 5 6 7 9, 15 10, 16 11 12 13 14 Mnemonic VDD1 GND1 VIA VIB VIC VID VDDL GNDISO VISO VOD VOC VOB VOA Description Primary Supply Voltage, 4.5 V to 5.5 V. Ground 1. Ground reference for isolator primary. Pin 2 and Pin 8 are internally connected to each other, and it is recommended that both pins be connected to a common ground. Logic Input A. Logic Input B. Logic Input C. Logic Input D. Logic Power Supply Voltage. This pin must be connected to VDD1 and have a dedicated bypass capacitor. Ground Reference for Isolator Side 2. Pin 9 and Pin 15 are internally connected to each other, and it is recommended that both pins be connected to a common ground. Secondary Supply Voltage Output for External Loads, 5.0 V. These pins are not tied together internally and must be connected together on the PCB. Logic Output D. Logic Output C. Logic Output B. Logic Output A.
Table 10. Truth Table (Positive Logic)
VIx Input 1 High Low
1
VDD1/VDDL State Powered Powered
VDD1/VDDL Input (V) 5.0 5.0
VISO State Powered Powered
VISO Output (V) 5.0 5.0
VOx Output1 High Low
Operation Normal operation, data is high Normal operation, data is low
VIx and VOx refer to the input and output signals of a given channel (A, B, C, or D).
Rev. 0 | Page 8 of 16
ADuM5400 TYPICAL PERFORMANCE CHARACTERISTICS
Each voltage is relative to its respective ground; all typical specifications are at TA = 25C.
40 35 30
INPUT CURRENT (A)
4.0
4.0 3.5 3.0 2.5 2.0 1.5 1.0 IDD 0.5 0 6.5
5V IN/5V OUT
3.5 3.0 2.5 2.0 1.5 1.0 0.5
07509-005
POWER
EFFICIENCY (%)
20 15 10 5 0
0
0.02
0.04 0.06 0.08 OUTPUT CURRENT (A)
0.10
0.12
3.5
4.0
4.5
5.0
5.5
6.0
INPUT VOLTAGE (V)
Figure 4. Typical Power Supply Efficiency at 5 V/5 V
1.0 0.9 0.8
POWER DISSIPATION (W)
Figure 7. Typical Short-Circuit Input Current and Power vs. VDD1 Supply Voltage
VDD1 = 5V, VISO = 5V 0.7 0.6 0.5
OUTPUT VOLTAGE (500mV/DIV)
10% LOAD
0.4 0.3 0.2 0.1
07509-006
90% LOAD
DYNAMIC LOAD
0 0 0.02 0.04 0.06 IISO (A) 0.08 0.10 0.12
(100s/DIV)
Figure 5. Typical Total Power Dissipation vs. IISO with Data Channels Idle
0.12
Figure 8. Typical VISO Transient Load Response, 5 V Output, 10% to 90% Load Step
5V IN/5V OUT
0.08
0.06
0.04
0.02
07509-011
0
0.05
0.10
0.15
0.20
0.25
0.30
0.35
INPUT CURRENT (A)
07509-007
0
5V OUTPUT RIPPLE (10mV/DIV)
0.10
OUTPUT CURRENT (A)
BW = 20MHz (400ns/DIV)
Figure 6. Typical Isolated Output Supply Current, IISO, as a Function of External Load, No Dynamic Current Draw at 5 V/5 V
Figure 9. Typical VISO = 5 V Output Voltage Ripple at 90% Load
Rev. 0 | Page 9 of 16
07509-009
07509-008
0 3.0
POWER (W)
25
ADuM5400
20
3.0
16
2.5
SUPPLY CURRENT (mA)
SUPPLY CURRENT (mA)
2.0
12
5V IN/5V OUT
1.5
5V
8
1.0
4
0.5
07509-013
0
0
5
10 15 DATA RATE (Mbps)
20
25
0
0
5
10 15 DATA RATE (Mbps)
20
25
Figure 10. Typical ICH Supply Current per Forward Data Channel (15 pF Output Load)
Figure 11. Typical IISO(D) Dynamic Supply Current per Output (15 pF Output Load)
Rev. 0 | Page 10 of 16
07509-016
ADuM5400 TERMINOLOGY
IDD1(Q) IDD1(Q) is the minimum operating current drawn at the VDD1 pin when there is no external load at VISO and the I/O pins are operating below 2 Mbps, requiring no additional dynamic supply current. IDD1(D) IDD1(D) is the typical input supply current with all channels simultaneously driven at a maximum data rate of 25 Mbps with the full capacitive load representing the maximum dynamic load conditions. Treat resistive loads on the outputs separately from the dynamic load. IDD1(MAX) IDD1(MAX) is the input current under full dynamic and VISO load conditions. tPHL Propagation Delay tPHL propagation delay is measured from the 50% level of the falling edge of the VIx signal to the 50% level of the falling edge of the VOx signal. tPLH Propagation Delay tPLH propagation delay is measured from the 50% level of the rising edge of the VIx signal to the 50% level of the rising edge of the VOx signal. Propagation Delay Skew (tPSK) tPSK is the magnitude of the worst-case difference in tPHL and/or tPLH that is measured between units at the same operating temperature, supply voltages, and output load within the recommended operating conditions. Channel-to-Channel Matching Channel-to-channel matching is the absolute value of the difference in propagation delays between two channels when operated with identical loads. Minimum Pulse Width The minimum pulse width is the shortest pulse width at which the specified pulse width distortion is guaranteed. Maximum Data Rate The maximum data rate is the fastest data rate at which the specified pulse width distortion is guaranteed.
Rev. 0 | Page 11 of 16
ADuM5400 APPLICATIONS INFORMATION
The dc-to-dc converter section of the ADuM5400 works on principles that are common to most modern power supplies. It has a secondary side controller architecture with isolated pulsewidth modulation (PWM) feedback. VDD1 power is supplied to an oscillating circuit that switches current into a chip scale air core transformer. Power transferred to the secondary side is rectified and regulated to 5 V. The secondary (VISO) side controller regulates the output by creating a PWM control signal that is sent to the primary (VDD1) side by a dedicated iCoupler data channel. The PWM modulates the oscillator circuit to control the power being sent to the secondary side. Feedback allows for significantly higher power and efficiency. The ADuM5400 implements undervoltage lockout (UVLO) with hysteresis on the VDD1, VDDL, and VISO power supplies. This feature ensures that the converter does not enter oscillation due to noisy input power or slow power-on ramp rates. A minimum load current of 10 mA is recommended to ensure optimum load regulation. Smaller loads can generate excess noise on chip due to short or erratic PWM pulses. Excess noise generated this way can cause data corruption in some circumstances. length may result in data corruption. Consider a bypass capacitor between Pin 1 and Pin 8 and between Pin 9 and Pin 16 unless both common ground pins are connected together close to the package.
BYPASS < 2mm VDD1 GND1 VIA VIB VIC VID VDDL GND1 VISO GNDISO VOA VOB VOC VOD GNDISO
07509-017
ADuM5400
VISO
Figure 12. Recommended PCB Layout
PCB LAYOUT
The ADuM5400 digital isolator with integrated 0.5 W isoPower dc-to-dc converter requires no external interface circuitry for the logic interfaces. Power supply bypassing is required at the input and output supply pins (see Figure 12). Note that a low ESR bypass capacitor is required between Pin 1 and Pin 2, within 2 mm of the chip leads. The power supply section of the ADuM5400 uses a 180 MHz oscillator frequency to efficiently pass power through its chip scale transformers. In addition, normal operation of the data section of the iCoupler introduces switching transients on the power supply pins. Bypass capacitors are required and must provide transient suppression at several operating frequencies. Noise suppression requires a low inductance, high frequency capacitor that is effective at 180 MHz and 360 MHz. Ripple suppression and proper regulation require a large value capacitor to provide bulk current at 625 kHz. These are most conveniently connected between Pin 1 and Pin 2 for VDD1 and between Pin 15 and Pin 16 for VISO. To suppress noise and reduce ripple, a parallel combination of at least two capacitors is required. The recommended capacitor values are 0.1 F and 10 F for VDD1. The smaller capacitor must have low ESR; for example, use of a ceramic capacitor is advised. Note that the total lead length between the ends of the low ESR capacitor and the input power supply pin must not exceed 2 mm. Installing the bypass capacitor with traces more than 2 mm in
In applications involving high common-mode transients, ensure that board capacitive coupling across the isolation barrier is minimized. Furthermore, design the board layout so that any coupling that does occur affects all pins on a given component side equally. Failure to ensure this can cause differential voltages between pins, exceeding the absolute maximum ratings for the device (specified in Table 7) and thereby leading to latch-up and/or permanent damage. The ADuM5400 is a power device that dissipates about 1 W of power when fully loaded and running at maximum speed. Because it is not possible to apply a heat sink to an isolation device, the device depends primarily on heat dissipation into the PCB through the GND pins. If the device is used at high ambient temperatures, provide a thermal path from the GND pins to the PCB ground plane. The board layout in Figure 12 shows enlarged pads for Pin 8 (GND1) and Pin 9 (GNDISO). Large diameter vias should be implemented from the pad to the ground, and power planes should be used to reduce inductance. Multiple vias in the thermal pads can significantly reduce temperatures inside the chip. The dimensions of the expanded pads are at the discretion of the designer and depend on the available board space.
EMI CONSIDERATIONS
The dc-to-dc converter section of the ADuM5400 components must operate at a very high frequency to allow efficient power transfer through the small transformers. This creates high frequency currents that can propagate in circuit board ground and power planes, causing edge emissions and dipole radiation between the primary and secondary ground planes. Grounded enclosures are recommended for applications that use these devices. If grounded enclosures are not possible, follow good RF design practices in the layout of the PCB. See www.analog.com for the most current PCB layout recommendations specifically for the ADuM5400.
Rev. 0 | Page 12 of 16
ADuM5400
PROPAGATION DELAY PARAMETERS
Propagation delay is a parameter that describes the time it takes a logic signal to propagate through a component (see Figure 13). The propagation delay to a logic low output may differ from the propagation delay to a logic high output.
INPUT (VIx) 50%
Given the geometry of the receiving coil in the ADuM5400 and an imposed requirement that the induced voltage be, at most, 50% of the 0.5 V margin at the decoder, a maximum allowable magnetic field is calculated as shown in Figure 14.
100
MAXIMUM ALLOWABLE MAGNETIC FLUX DENSITY (kgauss)
10
tPLH
OUTPUT (VOx)
tPHL
50%
07509-018
1
Figure 13. Propagation Delay Parameters
Pulse width distortion is the maximum difference between these two propagation delay values and is an indication of how accurately the timing of the input signal is preserved. Channel-to-channel matching refers to the maximum amount that the propagation delay differs between channels within a single ADuM5400 component. Propagation delay skew refers to the maximum amount that the propagation delay differs between multiple ADuM540x components operating under the same conditions.
0.1
0.01
100k 10k 1M 10M MAGNETIC FIELD FREQUENCY (Hz)
100M
Figure 14. Maximum Allowable External Magnetic Flux Density
DC CORRECTNESS AND MAGNETIC FIELD IMMUNITY
Positive and negative logic transitions at the isolator input cause narrow (~1 ns) pulses to be sent to the decoder via the transformer. The decoder is bistable and is, therefore, either set or reset by the pulses, indicating input logic transitions. In the absence of logic transitions at the input for more than 1 s, periodic sets of refresh pulses indicative of the correct input state are sent to ensure dc correctness at the output. If the decoder receives no internal pulses for more than approximately 5 s, the input side is assumed to be unpowered or nonfunctional, in which case the isolator output is forced to a default state by the watchdog timer circuit. This situation should occur in the ADuM5400 only during power-up and power-down operations. The limitation on the ADuM5400 magnetic field immunity is set by the condition in which induced voltage in the receiving coil of the transformer is sufficiently large to falsely set or reset the decoder. The following analysis defines the conditions under which this can occur. The 3.3 V operating condition of the ADuM5400 is examined because it represents the most susceptible mode of operation. The pulses at the transformer output have an amplitude of >1.0 V. The decoder has a sensing threshold of about 0.5 V, thus establishing a 0.5 V margin in which induced voltages can be tolerated. The voltage induced across the receiving coil is given by V = (-d/dt)rn2; n = 1, 2, ... , N where: is the magnetic flux density (gauss). N is the number of turns in the receiving coil. rn is the radius of the nth turn in the receiving coil (cm).
For example, at a magnetic field frequency of 1 MHz, the maximum allowable magnetic field of 0.2 kgauss induces a voltage of 0.25 V at the receiving coil. This is about 50% of the sensing threshold and does not cause a faulty output transition. Similarly, if such an event occurs during a transmitted pulse (and is of the worst-case polarity), the received pulse is reduced from >1.0 V to 0.75 V, which is still well above the 0.5 V sensing threshold of the decoder. The preceding magnetic flux density values correspond to specific current magnitudes at given distances from the ADuM5400 transformers. Figure 15 expresses these allowable current magnitudes as a function of frequency for selected distances. As shown in Figure 15, the ADuM5400 is extremely immune and can be affected only by extremely large currents operated at high frequency very close to the component. For example, at a magnetic field frequency of 1 MHz, a 0.5 kA current placed 5 mm away from the ADuM5400 is required to affect the operation of the component.
1000
MAXIMUM ALLOWABLE CURRENT (kA)
DISTANCE = 1m 100
10 DISTANCE = 100mm 1 DISTANCE = 5mm 0.1
1k
10k
100k
1M
10M
100M
MAGNETIC FIELD FREQUENCY (Hz)
Figure 15. Maximum Allowable Current for Various Current-to-ADuM5400 Spacings
Rev. 0 | Page 13 of 16
07509-020
0.01
07509-019
0.001 1k
ADuM5400
Note that in the presence of strong magnetic fields and high frequencies, any loops formed by PCB traces may induce error voltages sufficiently large to trigger the thresholds of succeeding circuitry. Exercise care in the layout of such traces to avoid this possibility. IISO(MAX) is the maximum external secondary side load current available at VISO. IISO(D)n is the dynamic load current drawn from VISO by an output channel, as shown in Figure 11. The preceding analysis assumes a 15 pF capacitive load on each data output. If the capacitive load is larger than 15 pF, the additional current must be included in the analysis of IDD1 and IISO(LOAD).
POWER CONSUMPTION
The VDD1 power supply input provides power to the iCoupler data channels, as well as to the power converter. For this reason, the quiescent currents drawn by the data converter and the primary and secondary I/O channels cannot be determined separately. All of these quiescent power demands have been combined into the IDD1(Q) current, as shown in Figure 16. The total IDD1 supply current is equal to the sum of the quiescent operating current; the dynamic current, IDD1(D), demanded by the I/O channels; and any external IISO load.
IDD1(Q) IDD1(D) CONVERTER PRIMARY E CONVERTER SECONDARY IISO
POWER CONSIDERATIONS
The ADuM5400 power input, the data input channels on the primary side, and the data output channels on the secondary side are all protected from premature operation by UVLO circuitry. Below the minimum operating voltage, the power converter holds its oscillator inactive, and all input channel drivers and refresh circuits are idle. Outputs are held in a low state to prevent transmission of undefined states during powerup and power-down operations. During application of power to VDD1, the primary side circuitry is held idle until the UVLO preset voltage is reached. The primary side input channels sample the input and send a pulse to the inactive secondary output. As the secondary side converter begins to accept power from the primary, the VISO voltage starts to rise. When the secondary side UVLO is reached, the secondary side outputs are initialized to their default low state until data, either from a logic transition or a dc refresh cycle, is received from the corresponding primary side input. It can take up to 1 s after the secondary side is initialized for the state of the output to correlate to the primary side input. The dc-to-dc converter section goes through its own power-up sequence. When UVLO is reached, the primary side oscillator also begins to operate, transferring power to the secondary power circuits. The secondary VISO voltage is below its UVLO limit at this point; the regulation control signal from the secondary is not being generated. The primary side power oscillator is allowed to free run in this circumstance, supplying the maximum amount of power to the secondary, until the secondary voltage rises to its regulation setpoint. This creates a large inrush current transient at VDD1. When the regulation point is reached, the regulation control circuit produces the regulation control signal that modulates the oscillator on the primary side. The VDD1 current is reduced and is then proportional to the load current. The inrush current is less than the short-circuit current shown in Figure 7. The duration of the inrush depends on the VISO load conditions and the current available at the VDD1 pin. Because the rate of charge of the secondary side is dependent on load conditions, the input voltage, and the output voltage level selected, ensure that the design allows the converter to stabilize before valid data is required.
IDDP(D)
IISO(D)
PRIMARY DATA I/O 4-CHANNEL
SECONDARY DATA I/O 4-CHANNEL
07509-021
Figure 16. Power Consumption Within the ADuM5400
Dynamic I/O current is consumed only when operating a channel at speeds higher than the refresh rate of fr. The dynamic current of each channel is determined by its data rate. Figure 10 shows the current for a channel in the forward direction, meaning that the input is on the VDD1 side of the part. The following relationship allows the total IDD1 current to be calculated: IDD1 = (IISO x VISO)/(E x VDD1) + ICHn; n = 1 to 4 (1) where: IDD1 is the total supply input current. ICHn is the current drawn by a single channel determined from Figure 10. IISO is the current drawn by the secondary side external load. E is the power supply efficiency at 100 mA load from Figure 4 at the VISO and VDD1 condition of interest. The maximum external load can be calculated by subtracting the dynamic output load from the maximum allowable load. IISO(LOAD) = IISO(MAX) - IISO(D)n; n = 1 to 4 (2) where: IISO(LOAD) is the current available to supply an external secondary side load.
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ADuM5400
When power is removed from VDD1, the primary side converter and coupler shut down when the UVLO level is reached. The secondary side stops receiving power and starts to discharge. The outputs on the secondary side hold the last state that they received from the primary until one of these events occurs: * * The UVLO level is reached and the outputs are placed in their high impedance state. The outputs detect a lack of activity from the inputs and the outputs transition to their default low state until the secondary power reaches UVLO and the outputs transition to their high impedance state. Bipolar ac voltage is the most stringent environment. A 50-year operating lifetime under the bipolar ac condition determines the maximum working voltage recommended by Analog Devices. In the case of unipolar ac or dc voltage, the stress on the insulation is significantly lower. This allows operation at higher working voltages while still achieving a 50-year service life. The working voltages listed in Table 8 can be applied while maintaining the 50-year minimum lifetime, provided that the voltage conforms to either the unipolar ac or dc voltage cases. Any cross-insulation voltage waveform that does not conform to Figure 18 or Figure 19 should be treated as a bipolar ac waveform, and its peak voltage limited to the 50-year lifetime voltage value listed in Table 8. The voltage presented in Figure 19 is shown as sinusoidal for illustration purposes only. It is meant to represent any voltage waveform varying between 0 V and some limiting value. The limiting value can be positive or negative, but the voltage cannot cross 0 V.
RATED PEAK VOLTAGE 0V
07509-022
THERMAL ANALYSIS
The ADuM5400 consists of four internal die attached to a split lead frame with two die attach paddles. For the purposes of thermal analysis, the die are treated as a thermal unit, with the highest junction temperature reflected in the JA from Table 2. The value of JA is based on measurements taken with the part mounted on a JEDEC standard 4-layer board with fine width traces and still air. Under normal operating conditions, the ADuM5400 operates at full load up to 85C and at derated load up to 105C.
INSULATION LIFETIME
All insulation structures eventually break down when subjected to voltage stress over a sufficiently long period. The rate of insulation degradation depends on the characteristics of the voltage waveform applied across the insulation. Analog Devices conducts an extensive set of evaluations to determine the lifetime of the insulation structure within the ADuM5400. Accelerated life testing is performed using voltage levels higher than the rated continuous working voltage. Acceleration factors for several operating conditions are determined, allowing calculation of the time to failure at the working voltage of interest. Table 8 summarizes the peak voltages for 50 years of service life in several operating conditions. In many cases, the working voltage approved by agency testing is higher than the 50-year service life voltage. Operation at working voltages higher than the service life voltage listed can lead to premature insulation failure. The insulation lifetime of the ADuM5400 depends on the voltage waveform type imposed across the isolation barrier. The iCoupler insulation structure degrades at different rates, depending on whether the waveform is bipolar ac, unipolar ac, or dc. Figure 17, Figure 18, and Figure 19 illustrate these different isolation voltage waveforms.
Figure 17. Bipolar AC Waveform
RATED PEAK VOLTAGE
07509-024
0V
Figure 18. DC Waveform
RATED PEAK VOLTAGE
07509-023
0V
Figure 19. Unipolar AC Waveform
Rev. 0 | Page 15 of 16
ADuM5400 OUTLINE DIMENSIONS
10.50 (0.4134) 10.10 (0.3976)
16 9
7.60 (0.2992) 7.40 (0.2913)
1 8
10.65 (0.4193) 10.00 (0.3937)
1.27 (0.0500) BSC 0.30 (0.0118) 0.10 (0.0039) COPLANARITY 0.10 0.51 (0.0201) 0.31 (0.0122)
2.65 (0.1043) 2.35 (0.0925)
0.75 (0.0295) 0.25 (0.0098)
8 0 0.33 (0.0130) 0.20 (0.0079)
45
SEATING PLANE
1.27 (0.0500) 0.40 (0.0157)
COMPLIANT TO JEDEC STANDARDS MS-013- AA CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.
Figure 20. 16-Lead Standard Small Outline Package [SOIC_W] Wide Body (RW-16) Dimensions shown in millimeters and (inches)
ORDERING GUIDE
Model ADuM5400ARWZ1, 2 ADuM5400CRWZ1, 2
1 2
Number of Inputs, VDD1 Side 4 4
Number of Inputs, VISO Side 0 0
Maximum Data Rate (Mbps) 1 25
Maximum Propagation Delay, 5 V (ns) 100 60
Maximum Pulse Width Distortion (ns) 40 6
Temperature Range -40C to +105C -40C to +105C
Package Description 16-Lead SOIC_W 16-Lead SOIC_W
032707-B
Package Option RW-16 RW-16
Tape and reel are available. The addition of an RL suffix designates a 13" (1,000 units) tape and reel option. Z = RoHS Compliant Part.
(c)2008 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D07509-0-10/08(0)
Rev. 0 | Page 16 of 16

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