component
UC3842BD1
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
markdownUC3842BD1
STMicroelectronics · AC-DC Controllers And Regulators · SO-8
UC3842BD1 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 for loop compensation control circuits. |
| 2 | VFB | input | Inverting input of error amplifier; connect switching power supply feedback through resistor divider network (−0.3 to 5.5 V absolute maximum). |
| 3 | ISENSE | input | Current sense input; voltage proportional to inductor current used by PWM to terminate output switch conduction (maximum input signal 0.9-1.1 V). |
| 4 | RT/CT | passive | Oscillator timing node; connect resistor RT to VREF and capacitor CT to ground; programs frequency from 49 kHz to 500 kHz maximum. |
| 5 | GROUND | power_in | Combined control circuitry and power ground; primary return for all logic circuits and bypass capacitors. |
| 6 | OUTPUT | output | PWM output stage directly drives N-channel MOSFET gates; sources and sinks ±1 A peak current with 50-150 ns rise and fall times. |
| 7 | VCC | power_in | Positive supply voltage input; 8.5-17.5 V operating range for UC3842B with 16 V start threshold and 10 V stop threshold. |
| 8 | VREF | power_in | Reference voltage output at 5.0 V nominal; supplies 50 mA charging current for RT/CT timing network capacitor. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | STMicroelectronics |
| Package | SO-8 |
| Category | Power Management (PMIC) |
| Pins | 8 |
CAD (KiCad official)
- Symbol:
UC3842BD1 - Footprint:
Package_SO:SOIC-8_3.9x4.9mm_P1.27mm - 3D model: SO-8 (KiCad packages3D, STEP)
- 3D model files:
uc3842bd1-etched.step/uc3842bd1-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);uc3842bd1.step/uc3842bd1.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: STMicroelectronics datasheet (15 pp, sha256
fedfd7362400f8b3, retrieved 2026-09-26, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.2, primaryclaude-haiku-4-5-20251001(text), consensusclaude-sonnet-4-6(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).