component
UC3843BD1
Public Made by Adomby adom
STMicroelectronics AC-DC Controllers And Regulators, SO-8. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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README
markdownUC3843BD1
STMicroelectronics · AC-DC Controllers And Regulators · SO-8
UC3843BD1 from STMicroelectronics, in a SO-8. 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 | COMP | output | Error Amplifier output made available for loop compensation. |
| 2 | VFB | input | Inverting input of the Error Amplifier; normally connected to switching power supply output through a resistor divider. |
| 3 | ISENSE | input | Voltage proportional to inductor current input; PWM uses this information to terminate output switch conduction. |
| 4 | RT/CT | passive | Oscillator frequency and maximum output duty cycle are programmed by connecting resistor RT to Vref and capacitor CT to ground; operation to 500kHz is possible. |
| 5 | GROUND | power_in | Combined control circuitry and power ground. |
| 6 | OUTPUT | output | Directly drives gate of power MOSFET; peak currents up to 1A are sourced and sunk by this pin. |
| 7 | VCC | power_in | Positive supply of the control IC. |
| 8 | Vref | power_in | Reference output providing charging current for capacitor CT through resistor RT. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | STMicroelectronics |
| Package | SO-8 |
| Category | Power Management (PMIC) |
| Pins | 8 |
CAD (KiCad official)
- Symbol:
UC3843BD1 - Footprint:
Package_SO:SOIC-8_3.9x4.9mm_P1.27mm - 3D model: SO-8 (KiCad packages3D, STEP)
- 3D model files:
uc3843bd1-etched.step/uc3843bd1-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);uc3843bd1.step/uc3843bd1.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: STMicroelectronics datasheet (15 pp, sha256
fedfd7362400f8b3, retrieved 2026-10-01, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-haiku-4-5-20251001(text), consensusclaude-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).