Is there a pin-compatible replacement for LM331AU-S5TR?

LM331A-S5TR is likely pin-compatible as it is from the same series and in the same SOT-23-5 package. However, a full pin-to-pin guarantee requires datasheet confirmation of the pinout and an engineering review of the relaxed offset voltage parameter. Other candidates are not pin-compatible due to significant electrical differences.

What risks should I check before replacing LM331AU-S5TR?

Before replacing, check three main risks: 1) Supply Voltage: Ensure the replacement handles your system's maximum voltage, as many alternatives are low-voltage only. 2) Output Type: The target is open-collector; a push-pull replacement will require circuit changes. 3) Precision: Check if a higher input offset voltage is acceptable for your application.

LM331AU-S5TR Alternatives, Datasheet & Cross Reference | 3PEAK

LM331AU-S5TR is a versatile 36V open-collector comparator from 3PEAK in a SOT-23-5 package. While no perfect drop-in is confirmed, LM331A-S5TR offers a very close functional match, requiring only a check on precision. Other alternatives are limited to low-voltage applications.

AI replacement insight

Electrical riskhigh

Many alternatives have incompatible output types (push-pull) or much lower voltage/temperature ratings.

Package risklow

The SOT-23-5 package is common, and several candidates match the form factor.

Sourcing risklow

The target is active, and multiple comparator options exist, though few match the high voltage rating.

Can it be replaced directly?

No guaranteed direct drop-in replacement has been identified. LM331A-S5TR is a very strong candidate but requires review of its higher offset voltage. Other candidates are not direct replacements due to major electrical differences.

Best replacement path

The best alternative is LM331A-S5TR from the same manufacturer, 3PEAK. It matches all critical parameters but has a slightly higher input offset voltage, which should be verified for precision-sensitive applications.

Main risk

The primary risk is selecting a low-voltage (5.5V max) substitute for an application that requires the target's 36V capability, leading to component failure.

Recommended alternatives

A very close alternative from the same manufacturer with matching package, voltage, and temperature range, but with a relaxed offset voltage.

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Alternative comparison matrix

Feature / factor	LM331AU-S5TR	LM331A-S5TR	LMV331IDBVR(MS)	Compatibility / risk
Package	SOT-23-5	SOT-23-5	SOT-23-5	SOT-23-5 — Package and pin count match.; LMV331IDBVR(MS): Package and pin count match.
Output Type	Open-Collector	Open-Collector	Open-Drain	Open-Collector / Open-Drain — Output type matches target.; LMV331IDBVR(MS): Open-Drain is functionally equivalent to Open-Collector.
Voltage	2.5V to 36V	2.5V to 36V	2.1V to 5.5V	2.5V to 36V / 2.1V to 5.5V — Supply voltage range matches.; LMV331IDBVR(MS): Significantly narrower supply voltage range.
Temperature	-40°C to 125°C	-40°C to 125°C	-40°C to +85°C	-40°C to 125°C / -40°C to +85°C — Operating temperature range matches.; LMV331IDBVR(MS): Reduced maximum operating temperature.
Offset Voltage	±3.0mV Max	±6mV Max	-	±6mV Max — Candidate has higher offset voltage, which may affect precision.
Current	150µA	-	50µA	50µA — Lower supply current is an improvement.

Application & sourcing insights

Questions & answers

The best alternative found is LM331A-S5TR. It is from the same manufacturer and matches the package, voltage range, and temperature range. However, it has a higher input offset voltage (±6mV vs ±3mV), so its impact on your circuit's precision must be evaluated.