MAX5527GUA+

Overview

The MAX5527GUA+ is a single-channel, linear-taper digital potentiometer manufactured by Analog Devices (Maxim Integrated). It provides an end-to-end resistance of 100kΩ with 64 discrete wiper tap positions. The device operates on a single supply voltage ranging from +2.7V to +5.5V and features an ultra-low static supply current of 1.5µA maximum. It utilizes a simple 2-wire serial interface for control and includes one-time programmable (OTP) memory to store the power-on reset position. The component is housed in an 8-pin µMAX package and is rated for operation across a temperature range of -40°C to +105°C.

Feature Summary

• One-Time Programmable Memory: Stores the wiper position after a six- or seven-pulse programming sequence; the seven-pulse option locks the wiper permanently.
• Digital Interface Control: Adjusts wiper position via a 2-wire up/down interface using Chip Select (CS) and Up/Down (U/D) inputs.
• Low Power Consumption: Features a maximum static supply current of 1.5µA, suitable for battery-operated applications.
• High Precision: Offers a low end-to-end temperature coefficient of 35ppm/°C and a ratiometric temperature coefficient of 5ppm/°C.

Applications

• LCD contrast control where voltage bias adjusts display contrast
• Programmable filters with adjustable gain and/or cutoff frequency
• Adjustable voltage references using feedback resistor networks

Procurement Notes

Verify the specific package type matches the design requirements, as the MAX5527 series is available in both TDFN-EP and µMAX packages. Confirm that the 100kΩ resistance value aligns with the circuit's impedance needs. Ensure the programming voltage source can provide at least 5mA during the OTP configuration phase.

Selection Notes

Select the MAX5527GUA+ when a fixed, non-adjustable resistance ratio is required after initial setup, utilizing the seven-pulse lockout feature. Compare against the MAX5528 (50kΩ) or MAX5529 (10kΩ) if lower resistance values are necessary. Consider the TDFN-EP variant if thermal dissipation through the exposed pad is beneficial for the application.

Part Context

The MAX5527GUA+ belongs to the MAX5527/MAX5528/MAX5529 family of one-time programmable, linear-taper digital potentiometers. These devices replace mechanical potentiometers by offering digital control over resistance ratios. The 'G' suffix indicates the extended industrial temperature range (-40°C to +105°C), while 'UA+' denotes the 8-pin µMAX package with lead-free/RoHS compliance.

Replacement Considerations

Direct functional replacements within the same family include the MAX5527GTA+ (TDFN-EP package) for identical electrical performance with a different footprint. For different resistance values, the MAX5528GUA+ (50kΩ) and MAX5529GUA+ (10kΩ) share the same pinout and interface but differ in end-to-end resistance specifications.

FAQ

How is the wiper position locked to prevent further adjustment?

The wiper position is locked by performing a seven-cycle CS pulse sequence during the one-time programming mode. This disables the up/down interface, effectively converting the device into a fixed resistor divider.

What are the timing requirements for the U/D input transitions?

The minimum U/D step low time (tIL) and high time (tIH) are both 100ns. The U/D frequency (fU/D) can reach up to 5MHz.

What is the default power-up wiper position if not programmed?

If the device is unprogrammed, the wiper defaults to midscale, which corresponds to tap 31 out of 64 positions.