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Contents

README

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KRA105S-RTK

KEC Semicon · Digital Transistors · SOT-23

KRA105S-RTK from KEC Semicon, 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 COMMON (EMITTER) passive Common emitter terminal of the built-in-bias PNP transistor, marked COMMON(+) in the equivalent circuit, with no separate voltage or current limit given for this pin.
2 IN (BASE) input Base input through the internal input resistor R1 (2.2 kΩ for KRA105S), with a rated input voltage of -12 V to 5 V for this type.
3 OUT (COLLECTOR) output Collector output with a rated output voltage of -50 V and output current of -100 mA, with device power dissipation of 200 mW.

Key specifications

Parameter Value
Manufacturer KEC Semicon
Package SOT-23
Category Transistors/Thyristors
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 Cut-off Current (KRA101S-106S, applies to KRA105S) IO(OFF) -500 nA VO=-50V, VI=0 2
DC Current Gain (KRA105S) GI 80 200 VO=-5V, IO=-10mA 2
Output Voltage (ON) (KRA101S-106S, applies to KRA105S) VO(ON) -0.1 -0.3 V IO=-10mA, II=-0.5mA 2
Input Voltage (ON) (KRA105S) VI(ON) -0.8 -1.1 V VO=-0.2V, IO=-5mA 2
Input Voltage (OFF) (KRA105S) VI(OFF) -0.5 -0.65 V VO=-5V, IO=-0.1mA 2
Input Current (KRA105S) II -3.6 mA VI=-5V 2
Input Resistor R1 (KRA105S) R1 1.54 2.2 2.86 kΩ 2
Resistor Ratio R2/R1 (KRA105S) R2/R1 17 21 26 2
Output Voltage (absolute maximum, KRA101S-106S) VO -50 V 1
Input Voltage (absolute maximum, KRA105S) VI -12 5 V 1
Output Current (absolute maximum, KRA101S-106S) IO -100 mA 1
Power Dissipation PD 200 mW 1
Junction Temperature Tj 150 1
Storage Temperature Range Tstg -55 150 1
Bias Resistor R2 (KRA105S nominal) R2 47 kΩ 1

CAD (KiCad official)

  • Symbol: KRA105S-RTK
  • Footprint: Package_TO_SOT_SMD:SOT-23
  • 3D model: SOT-23 (KiCad packages3D, STEP)
  • 3D model files: kra105s-rtk-etched.step / kra105s-rtk-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); kra105s-rtk.step / kra105s-rtk.glb are the bare package body.

Provenance

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

  • Datasheet: KEC Semicon datasheet (6 pp, sha256 db5b473a62ff76f3, retrieved 2026-10-19, 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