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STMicroelectronics LD1117S33CTR — Power Management (PMIC / Gate Driver)

STMicroelectronics LD1117S33CTR LDO Regulator, Fixed 3.3V

MPNLD1117S33CTR
Active

STMicroelectronics LD1117S33CTR, fixed 3.3V positive LDO regulator, 800mA output, 1.3V max dropout at full load, PSRR 75dB at 120Hz, SOT-223 surface-mount package, -40°C to 125°C operating range.

$0.20899Ref. price · indicative, final on quote
STMicroelectronics LD1117S33CTR datasheet (PDF)
PackagingTO-261-4, TO-261AA
RoHSROHS3 Compliant
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

LD1117S33CTR specifications
ParameterValue
Output typeFixed
MountingSurface Mount
Voltage - input15V
Voltage dropout1.3V @ 800mA
Voltage - output (Min (Fixed))3.3V
Output current800mA
Current - quiescent10 mA
Operating temperature-40°C~125°C
PSRR75dB (120Hz)
PackageTape & Reel (TR); Cut Tape (CT)
CaseTO-261-4, TO-261AA
Protection featuresOver Current, Over Temperature
Number of regulators1
Output configurationPositive

Product details

Dropout and input headroom — what the numbers mean

The 1.3V dropout at 800mA is the worst-case figure; typical dropout at lower currents is lower, but the max is what you design to. With a 15V absolute maximum input, you have plenty of headroom for 5V or 12V rails, but the quiescent current of 10 mA is on the higher side for battery-powered designs — this part is better suited to line-powered or moderate-current applications where the Iq is a small fraction of the load.

It is a standard ST product that moves through the usual distribution channels. No LTB window to watch.

Frequently asked questions

Can LD1117S33CTR replace LD1117V33?

LD1117V33 is the same base part in a different package (typically TO-220 or DPAK). The LD1117S33CTR is in SOT-223, so they are not pin-compatible — the board footprint differs. Functionally they are the same regulator, but the package change means a different PCB layout.

What is the closest functional second-source for LD1117S33CTR?

The ST LD39020DTPU33R is another fixed 3.3V LDO in a similar SOT-223 footprint, but it is rated for only 200mA output and has a lower 5.5V max input. It also includes an enable pin and soft-start. For a direct 800mA replacement, the LD1117S33CTR is the right call; the LD39020 is only a fit if your load is under 200mA and you need the enable feature.