MAX951EPA+

Overview

The MAX951EPA+ is an ultra-low-power, single-supply integrated circuit combining a micro-power operational amplifier, comparator, and precision reference within an 8-pin plastic DIP 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, ground-referenced inputs, and an internal 1.2V ±2% bandgap reference. Designed for battery-powered systems, it offers unity-gain stability for the op amp and includes internal hysteresis for clean comparator switching.

Feature Summary

• Combines op amp, comparator, and reference in an 8-pin μMAX-compatible package
• Ultra-low power consumption with 7μA typical supply current
• Rail-to-rail output swing and ground-referenced input range
• Internal 1.2V ±2% bandgap reference with ±3mV comparator hysteresis

Applications

• Battery-powered portable instruments and terminals
• Low-frequency local-area alarms and detectors
• Photodiode preamplifiers and infrared receivers
• Smoke detectors and safety sensors
• Smart cards and bar-code readers

Procurement Notes

Verify the specific suffix 'EPA' confirms the -40°C to +85°C temperature range and 8-pin Plastic DIP package format. Confirm RoHS compliance status via the manufacturer's latest documentation, as ordering suffixes may indicate environmental certifications rather than functional changes. Ensure the source document matches the exact part number for accurate electrical specifications.

Selection Notes

Select this component when system design requires minimal quiescent current alongside signal conditioning and threshold detection functions. The MAX951EPA+ is suitable for applications needing a stable reference voltage without external components. Consider the 7μA supply current impact on total battery life compared to higher-performance alternatives that may consume significantly more power.

Part Context

This device belongs to the MAX951–MAX954 family of ultra-low-power mixed-signal ICs. While other variants like the MAX952 offer decompensated op amps for higher bandwidth, the MAX951 provides unity-gain stability. The 'E' suffix denotes the industrial temperature range, and 'PA' specifies the through-hole plastic DIP packaging option available for prototyping or legacy board designs.

Replacement Considerations

Direct replacements include other members of the MAX95x family such as the MAX951ESA or MAX951EUA, provided the package type matches the PCB footprint. Verify that the replacement maintains the required unity-gain stability and supply current characteristics if low power is critical.

FAQ

What is the function of the REF pin on the MAX951?

The REF pin provides access to the internal 1.20V ±2% bandgap reference voltage. In the MAX951, this reference is also internally connected to the inverting input of the comparator.

Does the MAX951 require external bypass capacitors?

Power-supply bypass capacitors are not strictly required if the supply impedance is low, but it is good practice to bypass VDD with a 0.1μF capacitor to ground. The reference output should not be bypassed.

How does the internal hysteresis benefit the comparator?

The internal ±3mV hysteresis ensures clean output switching even with slow-moving input signals by increasing noise immunity and preventing oscillation near the trip point.