Is there a pin-compatible replacement for AMS1117-3.3?

Yes, many regulators in the 1117 family use a standard 4-pin SOT-223 pinout. Candidates like LD1117AG-33-AA3-A-R share the same package and pin count, making them likely pin-compatible. However, always verify the pin functions in the datasheet before substitution.

What risks should I check before replacing AMS1117-3.3?

Key risks include: 1) Electrical Stress: Ensure the replacement's max input voltage meets or exceeds the target's 18V. 2) Pinout: Verify the pin functions are identical. 3) Performance: Check dropout voltage, PSRR, and thermal characteristics.

AMS1117-3.3 Alternatives, Datasheet & Cross Reference | KEXIN

The AMS1117-3.3 is a popular 3.3V, 1A LDO voltage regulator in a SOT-223 package. Finding a suitable replacement involves matching key electrical parameters and physical characteristics like package and pinout.

AI replacement insight

Electrical riskhigh

Lower Vin(max) on candidates can lead to device failure if system voltage exceeds 15V.

Package risklow

Several candidates match the SOT-223 package and 4-pin count.

Can it be replaced directly?

No perfect drop-in replacement was found in this batch; the best candidates have a lower maximum input voltage, requiring design review.

Best replacement path

Prioritize candidates from the 1117 family with a 3.3V output, >=1A current, SOT-223 package, and a maximum input voltage of 18V or higher.

Main risk

Electrical overstress due to candidates having a lower maximum input voltage (15V) than the target (18V).

Recommended alternatives

A functional alternate in the same SOT-223 package with identical output, but a lower max input voltage.

View details

Alternative comparison matrix

Feature / factor	AMS1117-3.3	LD1117AG-33-AA3-A-R	LM1117S-3.3(MS)	Compatibility / risk
Output Voltage V	3.3V	3.3V	-	3.3V — Output voltage matches.
Output Current A	1.0A	1.0A	-	1.0A — Output current rating matches.
Input Voltage V	18V	15V	-	15V — Candidate max input voltage is lower.
Package	SOT-223	SOT-223	-	SOT-223 — Package type matches.
Pin Count	4	4	-	4 — Pin count matches.

Application & sourcing insights

Questions & answers

Parts like UTC's LD1117AG-33-AA3-A-R are strong functional alternates. They match the 3.3V/1A output and SOT-223 package, but have a lower max input voltage (15V vs 18V), which must be verified for your application.