MAX5478ETE+

Overview

The MAX5478ETE+ is a dual, nonvolatile, linear-taper digital potentiometer featuring an I2C-compatible serial interface. It provides two independent potentiometers with 256 tap positions and a nominal end-to-end resistance of 50kΩ. The device operates on a single supply voltage ranging from +2.7V to +5.25V. Key electrical characteristics include a maximum static supply current of 1µA, ±1 LSB integral nonlinearity (INL), and ±0.5 LSB differential nonlinearity (DNL) in voltage-divider mode. The internal EEPROM retains wiper position data for up to 50 years at +85°C.

Feature Summary

• Dual 256-Tap Nonvolatile Digital Potentiometers
• I2C-Compatible Serial Interface with Up to 400kbps Data Rate
• Power-On Recall of Wiper Position from Internal EEPROM
• EEPROM Write Protection via WP Pin

Applications

• Mechanical Potentiometer Replacement
• Low-Drift Programmable-Gain Amplifiers
• Volume Control
• Liquid-Crystal Display (LCD) Contrast Control

Procurement Notes

Verify the specific package variant during procurement. The suffix 'E' indicates a 16-pin TQFN-EP package, while 'U' denotes a 14-pin TSSOP. The trailing '+' signifies lead-free/RoHS compliance. Ensure the ordering suffix matches the required physical footprint and environmental specifications for the target application.

Selection Notes

Select the MAX5478ETE+ when a 50kΩ nominal resistance is required; the MAX5477 offers 10kΩ and the MAX5479 offers 100kΩ. All variants share identical pinouts and functionality. Verify that the system power supply remains within the +2.7V to +5.25V range and that the I2C bus pull-up resistors are appropriately sized for the desired clock speed.

Part Context

The MAX5478ETE+ belongs to the MAX5477/MAX5478/MAX5479 family of dual, nonvolatile, I2C-interface digital potentiometers. These devices replace mechanical potentiometers using a simple 2-wire digital interface. The family shares common features such as 256 tap points, nonvolatile memory, and low temperature coefficients, differing primarily in their nominal end-to-end resistance values.

Replacement Considerations

Direct functional replacements within the same package include the MAX5477ETE+ (10kΩ) and MAX5479ETE+ (100kΩ). For alternative packages, the MAX5478EUD+ provides the same 50kΩ specification in a 14-pin TSSOP format. Cross-model substitution requires verifying the required resistance value and ensuring compatibility with the existing I2C addressing scheme.