LDK120M33R from STMicroelectronics, in a SOT-23-5L. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	IN	power_in	Input supply voltage to the LDO. Operating range 1.9 V to 5.5 V (absolute max -0.3 V to +7 V). Typically bypassed with a 1 µF ceramic capacitor to GND.
2	GND	power_in	Common ground reference for the device. All voltages in the datasheet are referred to this pin.
3	EN	input	Enable logic input. Low (<=0.4 V) puts the LDO into shutdown (<1 µA); High (>=1.2 V) enables the regulator. Input current ~100 nA. Absolute max -0.3 V to VIN+0.3 V.
4	BYP	passive	Bypass capacitor pin for noise reduction on the fixed-output version. A 10 nF ceramic capacitor from BYP to GND reduces output noise (typ. 51 µVRMS with CBYP vs 148 µVRMS without). Optional - if unused, leave floating with no PCB routing. Absolute max 2 V.
5	OUT	power_out	Regulated 3.3 V output (±2% at 25 °C, ±3% over -40 °C to 125 °C). Delivers up to 200 mA. Requires a 1 µF (up to 22 µF) ceramic output capacitor for stability. Internally current-limited (~400 mA short-circuit) and thermally protected (160 °C shutdown).

Key specifications

Parameter	Value
Manufacturer	STMicroelectronics
Package	SOT-23-5L
Category	PMIC
Pins	5

Ordering variants

Same part, different packaging or reel option.

LDK120M33R
LDK120C33R
LDK120PU33R

CAD (KiCad official)

Symbol: LDK120M33R
Footprint: Package_TO_SOT_SMD:SOT-23-5
3D model: SOT-23-5L (KiCad packages3D, STEP)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: STMicroelectronics datasheet (None pp, sha256 1684d802fa69801e, retrieved 2026-08-17, tier: manufacturer)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF