Is there a pin-compatible replacement for LM1117S-3.3(MS)?

Yes, many regulators in the 1117 family use the same SOT-223 pinout. However, pin compatibility does not guarantee electrical compatibility. Parameters like current rating, input voltage, and temperature range must be verified.

What risks should I check before replacing LM1117S-3.3(MS)?

Key risks include: 1) Minimum operating temperature (target is -40°C, many alternatives are 0°C or -20°C). 2) Output current (ensure it's at least 1A). 3) Dropout voltage (higher dropout may cause issues if input voltage is low).

LM1117S-3.3(MS) Alternatives, Datasheet & Cross Reference | MSKSEMI

The LM1117S-3.3(MS) is a common 3.3V, 1A LDO regulator in a SOT-223 package. Alternatives exist, but require careful review of operating temperature and dropout voltage to ensure system reliability.

AI replacement insight

Electrical riskmedium

Mismatches in temperature range and dropout voltage are common.

Package risklow

SOT-223 with the standard 1117 pinout is widely available.

Sourcing risklow

The 1117 LDO family is a multi-source commodity product.

Can it be replaced directly?

No direct, verified drop-in replacement has been identified. Alternatives require careful review, especially for operating temperature.

Best replacement path

Find a 1117-series LDO from a major vendor with a specified industrial temperature range (-40°C) and 1A output current.

Main risk

The primary risk is the minimum operating temperature; many common alternatives do not support the target's -40°C rating.

Recommended alternatives

A functional alternate with matching core specs but a narrower operating temperature range at the low end.

View details

Alternative comparison matrix

Feature / factor	LM1117S-3.3(MS)	LD1117AG-33-AA3-A-R	AMS1117-3.3	Compatibility / risk
Package	SOT-223	SOT-223	-	SOT-223 — Package matches.
Voltage	3.3V	3.3V	-	1.4V @ 1A — Slightly higher dropout voltage.
Current	1.0A	1.0A	-	1.0A — Output current matches.
Temperature	-40°C to 85°C	-20°C to +125°C	-	Varies by MFR — Often 0°C min, must be verified.

Application & sourcing insights

Questions & answers

A true drop-in replacement must match the 3.3V/1A output, SOT-223 package, and -40°C minimum operating temperature. Parts like UTC's LD1117AG-33 are functionally close but have a -20°C minimum temperature.