MAX5478
Dual, 256-Tap, Nonvolatile, I²C-Interface, Digital Potentiometers
Industry's Smallest, Dual, 256-Tap Digital Potentiometers Fit in 3mm x 3mm TQFN
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The MAX5477/MAX5478/MAX5479 nonvolatile, dual, linear-taper, digital potentiometers perform the function of a mechanical potentiometer, but replace the mechanics with a simple 2-wire digital interface. Each device performs the same function as a discrete potentiometer or variable resistor and has 256 tap points.
The devices feature an internal, nonvolatile EEPROM used to store the wiper position for initialization during power-up. A write-protect feature prevents accidental overwrites of the EEPROM. The fast-mode I²C-compatible serial interface allows communication at data rates up to 400kbps, minimizing board space and reducing interconnection complexity in many applications. Three address inputs allow a total of eight unique address combinations.
The MAX5477/MAX5478/MAX5479 provide three nominal resistance values: 10kΩ (MAX5477), 50kΩ (MAX5478), or 100kΩ (MAX5479). The nominal resistor 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 temperature- coefficient variable resistor, such as low drift, programmable gain-amplifier circuit configurations.
The MAX5477/MAX5478/MAX5479 are available in 16-pin 3mm x 3mm x 0.8mm TQFN and 14-pin 4.4mm x 5mm TSSOP packages. These devices operate over the extended -40°C to +85°C temperature range.Key Features
- Power-On Recall of Wiper Position from Nonvolatile Memory
- EEPROM Write Protection
- Tiny 3mm x 3mm x 0.8mm Thin QFN Package
- 70ppm/°C End-to-End Resistance Temperature Coefficient
- 10ppm/°C Ratiometric Temperature Coefficient
- Fast 400kbps I²C-Compatible Serial Interface
- 1µA (max) Static Supply Current
- Single-Supply Operation: +2.7V to +5.25V
- 256 Tap Positions per Potentiometer
- ±0.5 LSB DNL in Voltage-Divider Mode
- ±1 LSB INL in Voltage-Divider Mode
Applications/Uses
- Liquid-Crystal Display (LCD) Contrast Control
- Low-Drift Programmable-Gain Amplifiers
- Mechanical Potentiometer Replacements
- Volume Control
Technical Docs
| Data Sheet | Dual, 256-Tap, Nonvolatile, I²C-Interface, Digital Potentiometers | Jan 30, 2012 | |
| App Note | Using an Analog Voltage to Control a Digital Potentiometer | ||
| App Note | Logging the Linear Digital Potentiometer |
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Description
The MAX5478 evaluation system (EV system) consists of a MAX5478 evaluation kit (EV kit) and a companion command module interface board (CMODUSB).
The MAX5478 EV kit is an assembled and tested PC board that features the MAX5478 50kΩ linear-taper dual digital potentiometer. The MAX5478 IC features an internal nonvolatile EEPROM used to store the potentiometer's wiper position for initialization during power-up. The EEPROM is programmed through the I²C-compatible serial interface, transmitting at rates up to 400kbps. The MAX5478 address can be programmed by configuring three input pins for a total of eight unique address combinations. The MAX5478 EV kit can also be used to evaluate the MAX5477 (10kΩ) or the MAX5479 (100kΩ) dual digital potentiometers.
The EV kit also includes Windows® 98-/2000-/XP-compatible software that provides a professional user interface for exercising the MAX5478's features. The program is menu-driven and offers a graphical user interface (GUI) complete with control buttons and track bars.
The CMODUSB command module allows a personal computer (PC) to use its USB port to emulate an I²C 2-wire interface. Order the MAX5478EVCMODU for a complete PC-based EV kit. Order the MAX5478EVKIT if a CMODUSB command module or an I²C-compatible 2-wire interface system has already been purchased with a Maxim EV system.
Features
- Power-On Recall of Wiper Position from Nonvolatile Memory
- 2.7V to 5.25V Single-Supply Operation
- Configurable Device Address
- I²C-Compatible Serial Interface
- Easy-to-Use Menu-Driven Software
- Include Windows 98-/2000-/XP-Compatible Software and Demo PC Board
- Evaluate the MAX5477/MAX5478/MAX5479
- Assembled and Tested
Description
The MAX5478 evaluation system (EV system) consists of a MAX5478 evaluation kit (EV kit) and a companion command module interface board (CMODUSB).
The MAX5478 EV kit is an assembled and tested PC board that features the MAX5478 50kΩ linear-taper dual digital potentiometer. The MAX5478 IC features an internal nonvolatile EEPROM used to store the potentiometer's wiper position for initialization during power-up. The EEPROM is programmed through the I²C-compatible serial interface, transmitting at rates up to 400kbps. The MAX5478 address can be programmed by configuring three input pins for a total of eight unique address combinations. The MAX5478 EV kit can also be used to evaluate the MAX5477 (10kΩ) or the MAX5479 (100kΩ) dual digital potentiometers.
The EV kit also includes Windows® 98-/2000-/XP-compatible software that provides a professional user interface for exercising the MAX5478's features. The program is menu-driven and offers a graphical user interface (GUI) complete with control buttons and track bars.
The CMODUSB command module allows a personal computer (PC) to use its USB port to emulate an I²C 2-wire interface. Order the MAX5478EVCMODU for a complete PC-based EV kit. Order the MAX5478EVKIT if a CMODUSB command module or an I²C-compatible 2-wire interface system has already been purchased with a Maxim EV system.
Features
- Power-On Recall of Wiper Position from Nonvolatile Memory
- 2.7V to 5.25V Single-Supply Operation
- Configurable Device Address
- I²C-Compatible Serial Interface
- Easy-to-Use Menu-Driven Software
- Include Windows 98-/2000-/XP-Compatible Software and Demo PC Board
- Evaluate the MAX5477/MAX5478/MAX5479
- Assembled and Tested
Support & Training
Search our knowledge base for answers to your technical questions.
Filtered SearchOur dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal
Parameters
Key Features
- Power-On Recall of Wiper Position from Nonvolatile Memory
- EEPROM Write Protection
- Tiny 3mm x 3mm x 0.8mm Thin QFN Package
- 70ppm/°C End-to-End Resistance Temperature Coefficient
- 10ppm/°C Ratiometric Temperature Coefficient
- Fast 400kbps I²C-Compatible Serial Interface
- 1µA (max) Static Supply Current
- Single-Supply Operation: +2.7V to +5.25V
- 256 Tap Positions per Potentiometer
- ±0.5 LSB DNL in Voltage-Divider Mode
- ±1 LSB INL in Voltage-Divider Mode
Applications/Uses
- Liquid-Crystal Display (LCD) Contrast Control
- Low-Drift Programmable-Gain Amplifiers
- Mechanical Potentiometer Replacements
- Volume Control
Description
The MAX5477/MAX5478/MAX5479 nonvolatile, dual, linear-taper, digital potentiometers perform the function of a mechanical potentiometer, but replace the mechanics with a simple 2-wire digital interface. Each device performs the same function as a discrete potentiometer or variable resistor and has 256 tap points.
The devices feature an internal, nonvolatile EEPROM used to store the wiper position for initialization during power-up. A write-protect feature prevents accidental overwrites of the EEPROM. The fast-mode I²C-compatible serial interface allows communication at data rates up to 400kbps, minimizing board space and reducing interconnection complexity in many applications. Three address inputs allow a total of eight unique address combinations.
The MAX5477/MAX5478/MAX5479 provide three nominal resistance values: 10kΩ (MAX5477), 50kΩ (MAX5478), or 100kΩ (MAX5479). The nominal resistor 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 temperature- coefficient variable resistor, such as low drift, programmable gain-amplifier circuit configurations.
The MAX5477/MAX5478/MAX5479 are available in 16-pin 3mm x 3mm x 0.8mm TQFN and 14-pin 4.4mm x 5mm TSSOP packages. These devices operate over the extended -40°C to +85°C temperature range.Technical Docs
| Data Sheet | Dual, 256-Tap, Nonvolatile, I²C-Interface, Digital Potentiometers | Jan 30, 2012 | |
| App Note | Using an Analog Voltage to Control a Digital Potentiometer | ||
| App Note | Logging the Linear Digital Potentiometer |
Support & Training
Search our knowledge base for answers to your technical questions.
Filtered SearchOur dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal
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