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Contents

README

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UC3843D8TR

Texas Instruments · AC-DC Controllers And Regulators · SOIC-8

UC3843D8TR from Texas Instruments, in a SOIC-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 compensation pin with internal current limiting, allows zero duty cycle control by forcing externally to ground, accepts external compensation network components.
2 VFB input Inverting input to error amplifier with 2.5V reference voltage, used for voltage feedback control loop requiring minimal trace length and parasitic capacitance.
3 ISENSE input Primary-side current sense input connected to sense resistor, accepts maximum 1V signal, PWM comparator uses this to terminate output switch conduction and implement current mode control.
4 RT/CT bidirectional Oscillator timing pin with external RRT resistor to VREF and CCT capacitor to ground setting switching frequency per fOSC = 1.72/(RRT·CCT) from 100kHz to 500kHz.
5 GROUND power_in Analog ground and power return, serves as combined analog and power ground for device packages without separate PWRGND.
6 OUTPUT output Gate driver output providing ±1A peak current for direct MOSFET gate drive, actively held low when VCC is below UVLO threshold.
7 VCC power_in Analog controller bias supply input 12V to 28V, total current sum of static current (11-17mA) and average output current based on MOSFET gate charge and switching frequency.
8 VREF power_in 5V precision reference voltage output ±2% with 30mA maximum short circuit current, provides timing current to oscillator and bias to error amplifier reference input.

Key specifications

Parameter Value
Manufacturer Texas Instruments
Package SOIC-8
Category Power Management (PMIC)
Pins 8

CAD (KiCad official)

  • Symbol: UC3843D8TR
  • Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
  • 3D model: SOIC-8 (KiCad packages3D, STEP)
  • 3D model files: uc3843d8tr-etched.step / uc3843d8tr-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); uc3843d8tr.step / uc3843d8tr.glb are the bare package body.

Provenance

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

  • Datasheet: Texas Instruments datasheet (61 pp, sha256 0f875fd24cbb5fda, retrieved 2026-09-24, tier: lcsc)
  • Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
  • Extractor: parts-factory 2.0.0 / extract_pins 0.2, primary claude-haiku-4-5-20251001 (text), consensus claude-sonnet-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