Loads when you scroll to it. Unloads after 5 minutes in the background.

Symbol & Footprint

Schematic Symbol

Open full view ↗
Loads when you scroll to it. Unloads after 5 minutes in the background.

PCB Footprint

Open full view ↗
Loads when you scroll to it. Unloads after 5 minutes in the background.
Loads when you scroll to it. Unloads after 5 minutes in the background.
Download PDF
Contents

README

markdown

STD123S

Changjing · Bipolar (BJT) · SOT-23

STD123S from Changjing, in a SOT-23. 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 BASE input Base terminal, driven with IB=1mA in the stated on-resistance test (RON 0.6 Ω max) and with IB=50mA for VCE(sat) at IC=500mA, so the base drive must be sufficient for saturation.
2 EMITTER passive Emitter terminal; the datasheet limits emitter-base voltage to VEBO 6.5 V (maximum ratings), with emitter-base breakdown V(BR)EBO of 6.5 V and emitter cut-off current IEBO of 0.1 μA at VEB=6 V.
3 COLLECTOR passive Collector terminal; the datasheet limits VCBO to 20 V, VCEO to 15 V and collector current IC to 1 A, with total collector power dissipation PC of 350 mW.

Key specifications

Parameter Value
Manufacturer Changjing
Package SOT-23
Category Transistors/Thyristors
Pins 3

CAD (KiCad official)

  • Symbol: STD123S
  • Footprint: Package_TO_SOT_SMD:SOT-23
  • 3D model: SOT-23 (KiCad packages3D, STEP)
  • 3D model files: std123s-etched.step / std123s-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); std123s.step / std123s.glb are the bare package body.

Provenance

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

  • Datasheet: Changjing datasheet (4 pp, sha256 d2e01921cdde9b1b, retrieved 2026-10-09, tier: lcsc)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-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