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STMicroelectronics LM317T-DG — Power Management (PMIC / Gate Driver)

LM317T-DG STMicroelectronics Adjustable Linear Regulator

MPNLM317T-DG
Active

STMicroelectronics LM317T-DG, adjustable positive linear voltage regulator, 1.2 V to 37 V output, 1.5 A continuous, TO-220-3 through-hole package, active production, ROHS3 compliant.

$0.9500Ref. price · indicative, final on quote
STMicroelectronics LM317T-DG datasheet (PDF)
PackagingTO-220-3
RoHSROHS3 Compliant
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

LM317T-DG specifications
ParameterValue
Output typeAdjustable
MountingThrough Hole
Voltage - input40V
Voltage - output37V
Voltage - output (Min (Fixed))1.2V
Output current1.5A
Current - quiescent10 mA
Operating temperature0°C~125°C
PSRR80dB ~ 65dB (120Hz)
PackageTube
CaseTO-220-3
Protection featuresOver Current, Over Temperature, Short Circuit
Number of regulators1
Output configurationPositive

Product details

Adjustable 1.5 A positive regulator in TO-220

The LM317T-DG is a three-terminal adjustable positive voltage regulator from STMicroelectronics, delivering up to 1.5 A output current with an output voltage adjustable from 1.2 V to 37 V via two external resistors. Input voltage can go up to 40 V, and the device includes built-in over-current, over-temperature, and short-circuit protection — reducing the need for external supervisory circuitry.

PSRR and ripple rejection for noise-sensitive loads

Power supply rejection ratio is specified at 80 dB to 65 dB at 120 Hz — the higher figure at low frequencies means the regulator attenuates mains ripple well, but the drop at higher frequencies matters if the input rail carries switching noise above a few kilohertz.

Frequently asked questions

Is LM317T-DG a direct replacement for the standard LM317T?

Yes — the LM317T-DG is functionally identical to the standard LM317T and shares the same TO-220-3 pinout. The '-DG' suffix indicates ST's ROHS3-compliant version. It is a direct drop-in for any LM317T socket.

Does LM317T-DG require a heatsink at 1.5 A output?

At 1.5 A with a typical input-output differential of 3 V, the device dissipates about 4.5 W. The TO-220 package junction-to-ambient thermal resistance is around 50–65 °C/W without a heatsink, which would exceed the 125 °C maximum junction temperature. A heatsink is required for continuous operation at or near 1.5 A.

What protection features does LM317T-DG include?

The regulator integrates over-current limiting, over-temperature shutdown, and short-circuit protection — all internal, no external components needed.