What risks should I check before replacing L78L33ACUTR?

Before replacing, check three main risks: 1) Package Mismatch: ensure the replacement has the same SOT-89 footprint. 2) Pinout Incompatibility: verify the GND, Vout, and Vin pins are in the same positions. 3) Electrical Downgrades: confirm the replacement meets or exceeds the 125°C max temperature and other key specs.

L78L33ACUTR Alternatives, Datasheet & Cross Reference | STMicroelectronics

Find and compare replacements for the STMicroelectronics L78L33ACUTR, a 3.3V 100mA linear voltage regulator in a SOT-89 package. This guide analyzes potential pin-compatible and functional alternatives.

AI replacement insight

Package riskmedium

Some candidates have different packages or require specific variant ordering.

Electrical risklow

Most candidates offer upgraded current/temperature, but downgrades must be avoided.

Can it be replaced directly?

Direct replacement for L78L33ACUTR should use only Datasheet verified or Strong match candidates; many approved options still require engineering review.

Best replacement path

Start with AMS1117-3.3S, verifying the SOT-89 pinout. If a board redesign is possible, LDL1117S33R offers a performance upgrade.

Main risk

The primary risk is assuming pin-compatibility without verifying the candidate's datasheet, as pin assignments can vary between manufacturers.

Recommended alternatives

A potential pin-compatible alternative in a SOT-89 package with a higher 1A output current.

View details

Alternative comparison matrix

Feature / factor	L78L33ACUTR	AMS1117-3.3S	LDL1117S33R	LD1117-3.3	Compatibility / risk
Package	SOT-89	SOT-89	-	-	SOT-89 option available — Offered in multiple packages, SOT-89 variant must be specified.
Current	0.1A	1.0A	-	-	1.0A — Higher output current capability.
Temperature	0°C to 125°C	-40°C to 125°C	-	-	-40°C to 125°C — Wider operating range.
Voltage	30V (from datasheet)	18V	-	-	18V — Higher max input voltage.
Pinout	1:GND, 2:Vout, 3:Vin	Unknown	-	-	Unknown — Pinout must be verified against target.
Manufacturer	STMicroelectronics	-	STMicroelectronics	-	STMicroelectronics — Same manufacturer as target.

Application & sourcing insights

Questions & answers

Verified drop-in options for L78L33ACUTR are limited in the current batch. Review candidates marked Strong match or Datasheet verified, and validate package, pinout, and electrical limits before committing a BOM change.