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Rev 0; 8/03
Nonvolatile, 32-Position Digital Potentiometer
General Description
The DS4301 is a single 32-position linear digital potentiometer with 200k end-to-end resistance. The wiper setting is stored in EEPROM, so the DS4301 powers up with the last stored setting. The position of the wiper is controlled through a simple three-terminal increment/decrement interface. The DS4301 is ideal for white LED backlight brightness control. Its 8-pin SOP package, 2.4V to 5.5V supply range, and 200k endto-end resistance are especially suited for portable, battery-powered applications such as cellular telephones and PDAs.
Features
Single, 32-Position, 200k Linear Nonvolatile (NV) Potentiometer Ideal for Battery-Powered Applications Three-Terminal Increment/Decrement Interface to Adjust Wiper Position Wide Voltage Supply Range (2.4V to 5.5V) Command-Initiated NV Wiper Storage Operates Over the Industrial Temperature Range (-40C to +85C) Available in 8-Pin SOP
DS4301
Applications
White LED Backlight Brightness Control Portable Battery-Powered Devices such as PDAs and Cellular Phones Any Application that Requires a Small, Low-Cost NV Potentiometer
TOP VIEW
INC U/D H GND 1 2 3 4
Ordering Information
PART DS4301U-200 TEMP RANGE -40C to +85C PIN-PACKAGE 8 SOP (118 mil)
Pin Configuration
8 7
VCC CS L W
DS4301
6 5
SOP
Typical Operating Circuit
VCC VCC VCC H VREF 1F VCC 10H 10F MBR0540 1F
0.1F
DS4301
CONTROL INTERFACE CS INC U/D
W
VCC ADJ WHITE LED CURRENT REGULATOR GND
EXT CS FB RFB WHITE LEDs
L GND
PGND
______________________________________________ Maxim Integrated Products
1
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Nonvolatile, 32-Position Digital Potentiometer DS4301
ABSOLUTE MAXIMUM RATINGS
Voltage Range on VCC Pin Relative to Ground .....-0.5V to +6.0V Voltage Range on CS, INC, U/D, L, W, H Pins Relative to Ground*.....................................-0.5V to VCC + 0.5V Wiper Current .....................................................................3mA Operating Temperature Range ...........................-40C to +85C Programming Temperature.....................................0C to +70C Storage Temperature Range .............................-55C to +125C Soldering Temperature .......................................See IPC/JEDEC J-STD-020A Specification *Not to exceed 6.0V
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
RECOMMENDED DC OPERATION CONDITIONS
(VCC = VCC MIN to VCC MAX; TA = -40C to +85C, unless otherwise specified.)
PARAMETER Supply Voltage Input Logic 1 (CS, INC, U/D) Input Logic 0 (CS, INC, U/D) Resistor Inputs Wiper Current SYMBOL VCC VIH VIL L, H, W IW (Note 1) CONDITIONS MIN +2.4 0.7 x VCC -0.3 -0.3 -1 TYP MAX +5.5 VCC + 0.3 +0.3 x VCC VCC + 0.3 +1 UNITS V V V V mA
DC ELECTRICAL CHARACTERISTICS
(VCC = VCC MIN to VCC MAX; TA = -40C to +85C, unless otherwise specified.)
PARAMETER Input Leakage Standby Current (Note 2) Digital Input Capacitance SYMBOL IL ISTBY CI/O 3V 5V CONDITIONS MIN -1 30 15 TYP MAX +1 60 60 10 UNITS A A pF
ANALOG RESISTOR CHARACTERISTICS
(VCC = VCC MIN to VCC MAX; TA = -40C to +85C, unless otherwise specified.)
PARAMETER End-to-End Resistor Tolerance Wiper Resistance Absolute Linearity Relative Linearity End-to-End Temp Coefficient Ratiometric Temp Coefficient RW (Note 3) (Note 4) -0.5 -0.25 -250 7 SYMBOL TA = +25C CONDITIONS MIN -20 500 TYP MAX +20 2000 +0.5 +0.25 +250 UNITS % LSB LSB ppm/C ppm/C
2
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Nonvolatile, 32-Position Digital Potentiometer
AC ELECTRICAL CHARACTERISTICCS
(VCC = VCC MIN to VCC MAX; TA = -40C to +85C. See Figure 2 for timing diagram.)
PARAMETER CS to INC Setup U/D to INC Setup INC Low Period INC High Period INC Inactive to CS Inactive CS Deselect Time Wiper Change to INC Low INC Rise and Fall Times INC Low to CS Inactive Wiper Storage Time CS Low Pulse Wiper Load Time Power-Up Time SYMBOL tCI tDI tIL tIH tIC tCPH tIW tR, tF tIK tWST tCLP tWLT tPU (Note 7) (Note 8) (Note 5) (Note 6) 100 500 2 50 10 CONDITIONS MIN 50 100 50 100 500 100 200 5 TYP MAX UNITS ns ns ns ns ns ns ns s ns ms ns s ms
DS4301
NONVOLATILE MEMORY CHARACTERISTICS
(VCC = VCC MIN to VCC MAX)
PARAMETER EEPROM Write Cycles SYMBOL +70C (Note 9) CONDITIONS MIN 50,000 TYP MAX UNITS
Note 1: Note 2: Note 3: Note 4: Note 5: Note 6: Note 7: Note 8: Note 9:
All voltages are referenced to ground. STBY specified for VCC equal to 3.0V and 5.0V while control port logic pins are driven to VCC or GND. Absolute linearity is used to determine wiper voltage versus expected voltage as determined by wiper position. Relative linearity is used to determine the change of wiper voltage between two adjacent wiper positions. The INC low to CS inactive time is the transition time that allows the three control pins to become inactive without writing the wiper position to the EEPROM. Wiper storage time is the time required for the wiper position to be written to the EEPROM. During this time, the three-terminal interface is inactive. Wiper load time is specified as the time required to load the wiper position stored in EEPROM once VCC has reached a stable operating voltage greater than or equal to VCC MIN. Power-up time is specified as the time required before the three control pins become active once a stable power supply level of at least VCC MIN has been reached. The maximum number of EEPROM write cycles is guaranteed by design and is not tested in production.
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Nonvolatile, 32-Position Digital Potentiometer DS4301
Typical Operating Characteristics
(VCC = 5.0V; TA = +25C, unless otherwise noted.)
W-L RESISTANCE vs. POTENTIOMETER SETTING
DS4301 toc02
SUPPLY CURRENT vs. VOLTAGE
DS4301 toc01
SUPPLY CURRENT vs. TEMPERATURE
30 25 SUPPLY CURRENT (A) VCC = 3V 20 15 VCC = 5V 10 5 CS = INC = U/D = VCC 0 -40 -15 10 35 60 85 200 175 W-L RESISTANCE (k) 150 125 100 75 50
CS = INC = U/D = VCC 30 SUPPLY CURRENT (A) 25 20 15 10 5 0 0 1 2 3 4 5 VOLTAGE (V) POWER-UP POWER-DOWN
AT VCC = 5V AND 3V
25 0 0 5 10 15 20 25 30
TEMPERATURE (C)
POTENTIOMETER SETTING (DEC)
W-L RESISTANCE vs. SUPPLY VOLTAGE (POWER-UP)
DS4301 toc04
W-L RESISTANCE vs. SUPPLY VOLTAGE (POWER-DOWN)
DS4301 toc05
WIPER RESISTANCE vs. WIPER VOLTAGE
350 WIPER RESISTANCE () 300 VCC = 3V 250 200 150 100 50 VCC = 5V
DS4301 toc06
250 >1M 200 W-L RESISTANCE (k)
250 >1M 200 W-L RESISTANCE (k)
400
150 WIPER = POS 15 100 EEPROM RECALL 50
150 WIPER = POS 15 100
50
0 0 1 2 3 4 5 SUPPLY VOLTAGE (V)
0 0 1 2 3 4 5 SUPPLY VOLTAGE (V)
0 0 1 2 3 4 5 WIPER VOLTAGE (V)
ABSOLUTE LINEARITY vs. WIPER POSITION
DS4301 toc07
RELATIVE LINEARITY vs. WIPER POSITION
DS4301 toc08
VOLTAGE DIVIDER PERCENT CHANGE FROM +25C vs. TEMPERATURE
0.04 % CHANGE (FROM +25C) 0.03 0.02 0.01 0 -0.01 -0.02 -0.03 -0.04 -0.05 WIPER = POS 7 tc = 2.72ppm/C WIPER = POS 23 tc = 0ppm/C WIPER = POS 15 tc = 0.64ppm/C WIPER = POS 15 tc = 1.37ppm/C WIPER = POS 7 tc = 2.72ppm/C
DS4301 toc09
0.25 0.20 ABSOLUTE LINEARITY (LSB) 0.15 0.10 0.05 0 -0.05 -0.10 -0.15 -0.20 -0.25 0 10 20 30 WIPER POSITION (DEC)
0.25 0.20 ABSOLUTE LINEARITY (LSB) 0.15 0.10 0.05 0 -0.05 -0.10 -0.15 -0.20 -0.25 0 10 20 30 WIPER POSITION (DEC)
0.05
-40
-15
10
35
60
85
TEMPERATURE (C)
4
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DS4301 toc03
35
Nonvolatile, 32-Position Digital Potentiometer DS4301
Typical Operating Characteristics (continued)
(VCC = 5.0V; TA = +25C, unless otherwise noted.)
END-TO-END RESISTANCE PERCENT CHANGE FROM +25C vs. TEMPERATURE
DS4301 toc10
TEMPERATURE COEFFICIENT vs. POTENTIOMETER SETTING
TEMPERATURE COEFFICIENT (ppm/C) 8 6 4 2 0 -2 -4 -6 -8 -10 25C TO 85C +25C TO -40C
DS4301 toc11
5 4 % CHANGE (FROM +25C) 3 2 1 0 -1 -2 -3 -4 -5 -40 -20 0 20 40 60 80 TEMPERATURE (C) -148.38ppm/C = tc -37.18ppm/C = tc
10
0
5
10
15
20
25
30
POTENTIOMETER SETTING (DEC)
Pin Description
PIN 1 NAME INC FUNCTION Increment/Decrement Wiper Control. When INC transitions from high-to-low, the wiper moves in the direction established by the state of the U/D pin. Up/Down Control. Sets the directions of wiper movement. When set to a high state, a high-to-low transition on the INC pin increments the wiper. When set to a low state, a high-to-low transition on the INC pin decrements the wiper. High-End Terminal of the Potentiometer Ground Terminal Wiper Terminal of the Potentiometer Low-End Terminal of the Potentiometer Chip Select. When set to a low state, the wiper position can be adjusted using U/D and INC. When in a high-state, activity on INC and U/D does not affect or change the wiper position. Power Supply Terminal
2 3 4 5 6 7 8
U/D H GND W L CS VCC
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Nonvolatile, 32-Position Digital Potentiometer DS4301
Wiper Control
VCC POS 31 VCC CS INC U/D GND NONVOLATILE MEMORY CONTROL LOGIC UNIT 5-BIT WIPER SETTING POS 0 L W H
Figure 1. Block Diagram
Detailed Description
The DS4301 is a single nonvolatile digital potentiometer. This 32-position linear potentiometer has an end-toend resistance of 200k, and operates over a wide 2.4V to 5.5V supply voltage range. The wiper position is controlled by the three interface pins (U/D, CS, and INC), and the wiper setting can be stored in EEPROM on command.
Power-Up
On power-up, once a stable supply voltage of VCC MIN has been reached, the stored wiper setting is loaded from the EEPROM within tWLT. Also on power-up, the DS4301 wiper control pins become active approximately t PU after a stable supply voltage of V CC MIN has been reached.
WIPER NON-STORAGE CONDITION CS VIL INC tCI VIL tDI VIL tIW POSITION X WIPER POSITION tIW POSITION X + 1 POSITION X tR tIH tIL VIH tIK tF
Adjusting the wiper of the DS4301 involves using the three control pins (U/D, CS, and INC). See the Timing Diagram in Figure 2. To enable wiper adjustment, a high-to-low transition on the CS pin is required. Hold CS low for the duration of the communication. Doing this enables the INC pin to change the wiper position. Set the U/D pin high to increment or low to decrement the wiper position. The state of the U/D pin should be set more than tDI before the INC signal is transitioned from high to low. After the CS pin is active low, a highto-low transition on the INC pin moves the wiper in the direction dictated by the U/D pin. Continue to pulse INC (high to low) until the desired wiper position is reached. On the last edge, hold the INC line low. With the desired wiper position set, there are two ways to proceed. One method terminates communication without allowing the value of the current wiper position to be written to the EEPROM. This is done by transitioning the CS signal to the high state before bringing the INC signal high. As long as the state of the CS pin is high before the state of the INC pin goes high, the current wiper setting is not written to EEPROM. Because the current wiper setting was not stored to the NV memory, the previously stored wiper setting, not the current wiper setting, is loaded from memory if power is cycled to the device The other method is used to store a new wiper setting in the EEPROM. This is done by bringing the state of the INC pin high for a time of tIC before bringing the state of the CS pin high. Once the states of both CS and INC pins are high, the current wiper setting is stored in EEPROM after a time of t WST. If power is
WIPER STORAGE CONDITION
tCLP
VIH
tCPH tWST tIC
U/D
POSITION X - 1
Figure 2. Timing Diagram 6 _____________________________________________________________________
Nonvolatile, 32-Position Digital Potentiometer
cycled to the device, the wiper setting that was just stored is the setting loaded on power-up. Wiper storage does not have to occur immediately after a change in wiper position. At anytime the current wiper position can be stored to the EEPROM by simply issuing a low pulse to the CS pin for tCLP while the INC pin remains in a high state. The wiper does not move during this action and the current wiper setting is stored in EEPROM after tWST. For applications that require a specific wiper setting to be loaded on power-up and never changed, write the desired wiper setting to the EEPROM, then tie CS to VCC. Every time power is cycled to the DS4301, the desired wiper setting is loaded from EEPROM, and since CS is tied to VCC, no changes can be made to the wiper setting.
Chip Information
TRANSISTOR COUNT: 3512 SUBSTRATE INFO: P-substrate
DS4301
Package Information
For the latest package outline information, go to www.maxim-ic.com/DallasPackInfo.
EEPROM Characteristics
There is a limit to the number of times the EEPROM can be written to before a wear-out occurs (see the Nonvolatile Memory Characteristics table). After EEPROM wear-out occurs, the wiper can still be adjusted, however accurately storing the wiper position is no longer possible. When power is removed from the part, the current wiper position is lost. Upon power-up, the wiper setting stored in EEPROM is loaded within tWLT of VCC reaching a stable voltage level greater than or equal to VCC MIN. If EEPROM wear-out has occurred, the wiper setting that is loaded is unknown.
Application Information
To achieve the best results when using the DS4301, decouple the power supply with a 0.01F or 0.1F capacitor. Use a high-quality ceramic surface-mount capacitor when possible. Surface-mount components minimize lead inductance, improving performace. Ceramic capacitors tend to have adequate highfrequency response for decoupling applications.
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 7 (c) 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

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