Analog Devices Inc./Maxim Integrated MAX953EPA

Overview

MAX953EPA from Maxim Integrated is an ultra-low-power, single-supply analog IC integrating a unity-gain-stable op amp, rail-to-rail comparator, and no internal reference in an 8-pin plastic DIP package. It operates from 2.4V to 7V with 5μA typical supply current, supports common-mode input down to VSS and within 1.6V of VDD, and delivers rail-to-rail output swing - ideal for battery-powered smoke detectors requiring continuous sensing and low-quiescent alarm triggering.

For engineers reviewing the MAX953EPA datasheet, MAX953EPA pinout, MAX953EPA application, or MAX953EPA equivalent, key selection criteria include its 5μA supply current, absence of internal reference (enabling flexible external reference choice), unity-gain stability, rail-to-rail I/O, and −40°C to +85°C industrial temperature range.

Technical Context

The MAX953EPA integrates two independent signal chains: a micropower CMOS op amp optimized for unity-gain stability (20kHz GBW, 12.5V/ms slew rate) and a comparator with ±3mV internal hysteresis, 22μs propagation delay at 10mV overdrive, and rail-to-rail CMOS output capable of sourcing up to 40mA continuously. Both blocks share a common 2.4V–7V supply and feature rail-in/rail-out operation.

No internal voltage reference is included - unlike MAX951/MAX952 - making the MAX953EPA suitable for applications requiring externally set thresholds or higher-accuracy references. Input bias current is ≤0.05nA, and DC open-loop gain exceeds 100V/mV under 100kΩ load, ensuring precision in high-impedance sensor interfaces.

Key Specifications

Pinout & Package

MAX953EPA uses an 8-pin plastic DIP (dual in-line package) with 0.300" wide body and 0.100" lead pitch. Pin 1 is AMPOUT; pin 4 is VSS (ground); pin 5 is COMPIN+; pin 6 is COMPIN− (not REF); pin 7 is COMPOUT; pin 8 is VDD. No internal reference is present - pin 6 functions solely as inverting comparator input.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar op amp + comparator applications.

Compared with MAX953ESA and MAX953EUA, the MAX953EPA offers through-hole mounting for prototyping and high-reliability industrial assemblies, while retaining identical electrical behavior - enabling drop-in functional replacement across packages where mechanical fit permits.

Availability

MAX953EPA is available at Aetrix Electronics and suitable for smoke detector manufacturing, battery-powered alarm systems, and infrared receiver front ends requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for MAX953EPA includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for industrial, medical, and consumer applications.

The MAX951–MAX954 family was engineered for ultra-low-power, single-supply sensor signal conditioning and threshold detection - targeting battery-operated safety and instrumentation systems where quiescent current and rail-to-rail operation are critical.

FAQ

Does MAX953EPA include an internal voltage reference?

No, MAX953EPA does not include an internal voltage reference. Unlike MAX951/MAX952, it omits the 1.2V bandgap reference - pin 6 is COMPIN−, not REF. This allows designers to use external references for higher accuracy or custom thresholds. The MAX953EPA datasheet explicitly states "MAX953 and MAX954 are offered without an internal reference," confirming this distinction.

What is the maximum capacitive load the MAX953EPA op amp can drive while remaining stable?

The MAX953EPA op amp is internally compensated for unity-gain stability and can drive up to 1000pF without external compensation. The datasheet specifies "Op Amp Capable of Driving up to 1000pF Load" and shows stable transient response in the Typical Operating Characteristics (TOC12). For loads >1000pF, a small series resistor (e.g., 10–50Ω) at the output is recommended to isolate capacitance.

Can MAX953EPA operate from a 2.4V supply, and what performance changes occur?

Yes, MAX953EPA is fully specified from 2.4V to 7V. At 2.4V, supply current remains ~5μA, common-mode input range is VSS to (VDD − 1.6V) = VSS to 0.8V, and rail-to-rail output swing is maintained (VOL ≈ VSS + 50mV, VOH ≈ VDD − 500mV). Gain bandwidth reduces slightly but remains adequate for DC–10kHz applications per the 20kHz GBW spec at 5V.

How does the internal hysteresis in MAX953EPA's comparator improve reliability?

The MAX953EPA comparator includes ±3mV internal hysteresis, which creates a 6mV input window between upper and lower trip points. This prevents oscillation or chatter when input signals cross the threshold slowly or contain noise - essential for reliable alarm triggering in smoke detectors or low-frequency sensors. The hysteresis is fixed and requires no external components.

Is MAX953EPA pin-compatible with other members of the MAX951–MAX954 family?

Yes, MAX953EPA shares identical pinout and package dimensions with MAX951EPA, MAX952EPA, and MAX954EPA - all use the same 8-pin plastic DIP. However, functional differences exist: MAX951/MAX952 include internal 1.2V reference (pin 6 = REF), while MAX953/MAX954 use pin 6 as COMPIN−. Swapping requires verifying reference architecture compatibility in the target circuit.