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