MAX951ESA+T

Overview

The MAX951ESA+T is an ultra-low-power, single-supply integrated circuit combining a micro-power operational amplifier, a comparator, and a precision reference within an 8-pin SO package. It operates from a supply voltage range of 2.7V to 7V with a typical supply current of 7μA. The device features rail-to-rail outputs and includes an internal 1.2V ±2% bandgap reference connected to the comparator's inverting input. The op amp is unity-gain stable, while the comparator provides clean switching through internal hysteresis.

Feature Summary

• Combines a micro-power op amp, comparator, and precision reference in a compact 8-pin package
• Ultra-low power consumption with typical supply current of 7μA for extended battery life
• Internal 1.2V ±2% bandgap reference ensures accurate threshold detection without external components
• Rail-to-rail output stages maximize dynamic range in low-voltage single-supply applications

Applications

• Battery-powered portable instruments and terminals
• Low-frequency local-area alarms and detectors
• Photodiode preamplifiers for optical sensing
• Smart card interface circuits
• Infrared receivers for remote control systems

Procurement Notes

Verify the specific suffix 'ESA' confirms the 8-pin SO package and -40°C to +85°C operating temperature range. Confirm RoHS compliance status via the manufacturer's official documentation as ordering suffixes may indicate environmental attributes only. Ensure the component source is an authorized distributor to guarantee authenticity and traceability.

Selection Notes

Select this part when design constraints require minimizing board space by integrating three functions into one package. Choose the MAX951 variant specifically when an internal reference is needed for the comparator threshold. Consider the MAX953 if the internal reference is unnecessary to reduce supply current to 5μA. Verify that the unity-gain stability meets the application's feedback requirements.

Part Context

This component belongs to the MAX951–MAX954 family of ultra-low-power mixed-signal devices. The family differentiates models based on the presence of an internal reference and the gain stability configuration of the operational amplifier. The MAX951 represents the configuration with both the internal reference and unity-gain stable op amp, distinguishing it from the decompensated variants in the series.

Replacement Considerations

Direct replacements must match the 8-pin SO package and single-supply operation. Evaluate alternatives based on comparable supply current levels below 10μA and rail-to-rail output capabilities. Ensure any substitute maintains similar input offset voltage and common-mode input range specifications for direct pin-compatible integration.

FAQ

How does the internal reference affect the comparator operation?

In the MAX951, the internal 1.2V ±2% bandgap reference is connected directly to the comparator's inverting input (COMPIN-). This sets a fixed threshold voltage for the noninverting input, eliminating the need for external resistor dividers to establish the trip point.

What is the purpose of the internal hysteresis?

The comparator includes ±3mV of internal hysteresis to ensure clean output switching even when processing slow-moving input signals. This feature increases noise immunity and prevents output oscillation caused by signal noise near the threshold voltage.