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STMicroelectronics L6981N33DR — Discrete Semiconductors

STMicroelectronics L6981N33DR Buck Converter, 1.5A

MPNL6981N33DR
End of Life

STMicroelectronics L6981N33DR, step-down buck converter, 1.5A output, 3.3V fixed, 400kHz switching, synchronous rectification, 8-SOIC package.

$3.02Ref. price · indicative, final on quote
STMicroelectronics L6981N33DR datasheet (PDF)
Packaging8-SOIC (0.154", 3.90mm Width)
RoHSROHS3 Compliant
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

L6981N33DR specifications
ParameterValue
Output typeFixed
MountingSurface Mount
Voltage - input3.5V
Voltage - output (Min (Fixed))3.3V
Output current1.5A
Frequency - switching400kHz
I/O channels1
Operating temperature-40°C ~ 150°C (TJ)
PackageTape & Reel (TR); Cut Tape (CT)
FunctionStep-Down
TopologyBuck
Case8-SOIC (0.154\", 3.90mm Width)
Output configurationPositive
Synchronous rectifierYes

Product details

Key parametrics and fit decision

The L6981N33DR is a 1.5A step-down buck converter from STMicroelectronics, part of the L6981 family, with a fixed 3.3V output and synchronous rectification for improved efficiency at light loads. Input range spans 3.5V to 38V, so it can regulate a 3.3V rail from a 5V, 12V, or 24V supply — common in industrial control, automotive body electronics, and distributed power architectures. Switching at 400kHz, the internal synchronous rectifier eliminates the external catch diode and keeps the inductor small enough for a compact layout on a 2-layer board.

Frequently asked questions

What is the closest functional second-source to L6981N33DR?

The L6981C33DR is the closest peer within the same L6981 family: it shares the same fixed 3.3V output, 1.5A current rating, 400kHz switching frequency, synchronous rectification, and 8-SOIC package. The key difference is that the L6981N33DR is the standard version, while the C variant may have different control loop compensation or quiescent current — verify the BOM position's specific requirements before substituting.

What compliance documentation does STMicroelectronics provide for L6981N33DR?

The L6981N33DR is ROHS3 compliant, confirming it meets the EU RoHS directive's substance restrictions.