MAX5477/MAX5478/MAX5479
19-3379; Rev 5; 11/11
Dual, 256-Tap, Nonvolatile,
2
I C-Interface, Digital Potentiometers
General Description Features
The MAX5477/MAX5478/MAX5479 nonvolatile, dual, Power-On Recall of Wiper Position from
linear-taper, digital potentiometers perform the function Nonvolatile Memory
of a mechanical potentiometer, but replace the
EEPROM Write Protection
mechanics with a simple 2-wire digital interface. Each
Tiny 3mm x 3mm x 0.8mm Thin QFN Package
device performs the same function as a discrete poten-
tiometer or variable resistor and has 256 tap points. 70ppm/C End-to-End Resistance Temperature
Coefficient
The devices feature an internal, nonvolatile EEPROM
used to store the wiper position for initialization during 10ppm/C Ratiometric Temperature Coefficient
power-up. A write-protect feature prevents accidental
2
Fast 400kbps I C-Compatible Serial Interface
2
overwrites of the EEPROM. The fast-mode I C-compati-
1A (max) Static Supply Current
ble serial interface allows communication at data rates
up to 400kbps, minimizing board space and reducing Single-Supply Operation: +2.7V to +5.25V
interconnection complexity in many applications. Three
256 Tap Positions per Potentiometer
address inputs allow a total of eight unique address
0.5 LSB DNL in Voltage-Divider Mode
combinations.
1 LSB INL in Voltage-Divider Mode
The MAX5477/MAX5478/MAX5479 provide three nomi-
nal resistance values: 10k (MAX5477), 50k
(MAX5478), or 100k (MAX5479). The nominal resistor
Functional Diagram
temperature coefficient is 70ppm/C end-to-end and
10ppm/C ratiometric. The low temperature coefficient
makes the devices ideal for applications requiring a low-
HA
V
DD
8-BIT
temperature-coefficient variable resistor, such as low-
8 8 256 256
SHIFT
16-BIT
POSITION
drift, programmable gain-amplifier circuit configurations. GND
REGISTER WA
LATCH
DECODER
The MAX5477/MAX5478/MAX5479 are available in 16-
POR
LA
pin 3mm x 3mm x 0.8mm TQFN and 14-pin 4.4mm x
16-BIT
SDA
5mm TSSOP packages. These devices operate over
HB
2 NV
I C
the extended -40C to +85C temperature range.
MEMORY
SCL
256
INTERFACE 256
8
POSITION
WB
WP
DECODER
Applications
MAX5477
A0
LB
Mechanical Potentiometer Replacement MAX5478
A1
MAX5479
A2
Low-Drift Programmable-Gain Amplifiers
Volume Control
Pin Configurations appear at end of data sheet.
Liquid-Crystal Display (LCD) Contrast Control
Ordering Information/Selector Guide
END-TO-END
PART TEMP RANGE PIN-PACKAGE TOP MARK
RESISTANCE (k )
MAX5477ETE+T -40C to +85C 16 TQFN-EP* 10 ABO
MAX5477EUD+ -40C to +85C 14 TSSOP 10
MAX5478ETE+T -40C to +85C 16 TQFN-EP* 50 ABP
MAX5478EUD+ -40C to +85C 14 TSSOP 50
MAX5479ETE+T -40C to +85C 16 TQFN-EP* 100 ABQ
MAX5479EUD+ -40C to +85C 14 TSSOP 100
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
*EP = Exposed pad.
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxims website at www.maxim-ic.com.
EVALUATION KIT
AVAILABLE2
Dual, 256-Tap, Nonvolatile, I C-Interface,
Digital Potentiometers
ABSOLUTE MAXIMUM RATINGS
SDA, SCL, V to GND.........................................-0.3V to +6.0V Operating Temperature Range ...........................-40C to +85C
DD
All Other Pins to GND.................................-0.3V to (V + 0.3V) Maximum Junction Temperature .....................................+150C
DD
Maximum Continuous Current into H_, L_, and W_ Storage Temperature Range .............................-65C to +150C
MAX5477......................................................................5.0mA Lead Temperature (soldering, 10s) .................................+300C
MAX5478......................................................................1.3mA Soldering Temperature (reflow) .......................................+260C
MAX5479......................................................................0.6mA
Continuous Power Dissipation (T = +70C)
A
16-Pin TQFN (derate 17.5mW/C above +70C) .......1398mW
14-Pin TSSOP (derate 9.1mW/C above +70C) .........727mW
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.
PACKAGE THERMAL CHARACTERISTICS (Note 1)
TQFN TSSOP
Junction-to-Ambient Thermal Resistance ( ) ........57.2C/W Junction-to-Ambient Thermal Resistance ( ) ......100.4C/W
JA JA
Junction-to-Case Thermal Resistance ( ) ................40C/W Junction-to-Case Thermal Resistance ( ) ................30C/W
JC JC
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
ELECTRICAL CHARACTERISTICS
(V = +2.7V to +5.25V, H_ = V , L_ = GND, T = -40C to +85C, unless otherwise noted. Typical values are at V = +5V,
DD DD A DD
T = +25C.) (Note 2)
A
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
DC PERFORMANCE (VOLTAGE-DIVIDER MODE)
Resolution 256 Taps
Integral Nonlinearity INL (Note 3) 1 LSB
Differential Nonlinearity DNL (Note 3) 0.5 LSB
Dual Code Matching R0 and R1 set to same code (all codes) 1 LSB
End-to-End Resistance
TC 70 ppm/C
R
Temperature Coefficient
Ratiometric Resistance
10 ppm/C
Temperature Coefficient
MAX5477 -4
Full-Scale Error MAX5478 -0.6 LSB
MAX5479 -0.3
MAX5477 4
Zero-Scale Error MAX5478 0.6 LSB
MAX5479 0.3
DC PERFORMANCE (VARIABLE-RESISTOR MODE)
V = 3V 3
DD
Integral Nonlinearity (Note 4) INL LSB
V = 5V 1.5
DD
MAX5477 1
Differential Nonlinearity (Note 4) DNL LSB
MAX5478 1
MAX5479 1
2 _______________________________________________________________________________________
MAX5477/MAX5478/MAX5479