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Contents

README

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LD2981CU33TR

STMicroelectronics · Linear Voltage Regulators (LDO) · SOT-89-3

LD2981CU33TR from STMicroelectronics, in a SOT-89-3. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 VOUT power_out Regulated output port (3.3 V fixed for LD2981CU33TR), guaranteed up to 100 mA, with 2.2 µF suggested minimum low-ESR ceramic output capacitor for 2.85 to 3.3 V versions.
2 GND power_in Ground pin.
3 VIN power_in Input port with operating input voltage 2.5 to 16 V (absolute maximum -0.3 to 16 V) and 1 µF input capacitor required.

Key specifications

Parameter Value
Manufacturer STMicroelectronics
Package SOT-89-3
Category Power Management ICs
Pins 3

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter Symbol Min Typ Max Unit Conditions Page
Output voltage VO 3.258 3.3 3.341 V IO = 1 mA 10
Output voltage VO 3.234 3.366 V IO = 1 to 100 mA 10
Output voltage VO 3.184 3.415 V IO = 1 to 100 mA, TJ = -40 to 125 °C 10
Operating input voltage VOP 2.5 16 V 10
Line regulation ΔVO 0.003 0.014 %/V VO(NOM) + 1 < VIN < 16 V, IO = 1 mA 10
Line regulation ΔVO 0.032 %/V TJ = -40 to 125 °C 10
Quiescent current ON mode IQ 80 100 µA IO = 0 11
Quiescent current ON mode IQ 150 µA IO = 0, TJ = -40 to 125 °C 11
Quiescent current ON mode IQ 100 150 µA IO = 1 mA 11
Quiescent current ON mode IQ 200 µA IO = 1 mA, TJ = -40 to 125 °C 11
Quiescent current ON mode IQ 250 400 µA IO = 25 mA 11
Quiescent current ON mode IQ 800 µA IO = 25 mA, TJ = -40 to 125 °C 11
Quiescent current ON mode IQ 1000 1300 µA IO = 100 mA 11
Quiescent current ON mode IQ 2600 µA IO = 100 mA, TJ = -40 to 125 °C 11
Quiescent current OFF mode IQ 0.8 µA VINH < 0.3 V 11
Quiescent current OFF mode IQ 2 µA VINH < 0.15 V, TJ = -40 to 125 °C 11
Dropout voltage VDROP 1 3 mV IO = 0 11
Dropout voltage VDROP 5 mV IO = 0, TJ = -40 to 125 °C 11
Dropout voltage VDROP 7 10 mV IO = 1 mA 11
Dropout voltage VDROP 15 mV IO = 1 mA, TJ = -40 to 125 °C 11
Dropout voltage VDROP 70 100 mV IO = 25 mA 11
Dropout voltage VDROP 150 mV IO = 25 mA, TJ = -40 to 125 °C 11
Dropout voltage VDROP 180 250 mV IO = 100 mA 11
Dropout voltage VDROP 375 mV IO = 100 mA, TJ = -40 to 125 °C 11
Inhibit input logic low VINH 0.18 V LOW = Output OFF, TJ = -40 to 125 °C 11
Inhibit input logic high VINL 1.6 V HIGH = Output ON, TJ = -40 to 125 °C 11
Inhibit input current IINH 0 -1 µA VINH = 0 V, TJ = -40 to 125 °C 11
Inhibit input current IINH 5 15 µA VINH = 5 V, TJ = -40 to 125 °C 11
Short circuit current ISC 150 mA RL = 0 11
Supply voltage rejection SVR 63 dB CO = 10 µF, f = 1 KHz 11
Output noise voltage eN 160 µVRMS BW = 300 Hz to 50 KHz, CO = 10 µF 11
Thermal shutdown TSHDN 170 °C 11
DC input voltage VI -0.3 16 V 7
INHIBIT input voltage VINH -0.3 16 V 7
Storage temperature range TSTG -55 150 °C 7
Operating junction temperature range TOP -40 125 °C 7
Thermal resistance junction-case RthJC 15 °C/W SOT-89 6
Thermal resistance junction-ambient RthJA 110 °C/W SOT-89 6

CAD (KiCad official)

  • Symbol: LD2981CU33TR
  • Footprint: Package_TO_SOT_SMD:SOT-89-3
  • 3D model: SOT-89-3 (KiCad packages3D, STEP)
  • 3D model files: ld2981cu33tr-etched.step / ld2981cu33tr-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); ld2981cu33tr.step / ld2981cu33tr.glb are the bare package body.

Provenance

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

  • Datasheet: STMicroelectronics datasheet (27 pp, sha256 872f7e5b1c76b812, retrieved 2026-10-23, tier: manufacturer)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-sonnet-5-5 (text), consensus claude-sonnet-5-5 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF