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Contents

README

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UC3844D

Texas Instruments · AC-DC Controllers And Regulators · SOIC-14

UC3844D from Texas Instruments, in a SOIC-14. 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 connected to external compensation elements to modify error amplifier output; features internal current limiting and can be forced to GROUND for zero duty cycle control.
2 NC unconnected Not connected.
3 VFB input Inverting input to internal error amplifier for voltage feedback control; typical 2.5V setpoint with maximum 2.55V input range.
4 NC unconnected Not connected.
5 ISENSE input Current sensing input connected to current sensing resistor; PWM comparator uses this signal to terminate OUTPUT switch conduction with maximum 1V peak input and 3V/V gain.
6 NC unconnected Not connected.
7 RT/CT bidirectional Fixed frequency oscillator timing pin where timing resistor RRT connects to VREF and timing capacitor CCT connects to GROUND; frequency set by formula fOSC = 1.72/(RRT×CCT) with maximum 500kHz operation.
8 PWRGND power_in Power ground return path providing ground reference for output gate driver stage.
9 GROUND power_in Analog signal ground providing signal return path; serves as both power and analog ground where PWRGND is absent.
10 OUTPUT output Gate driver output providing and sinking peak current up to 1A for direct MOSFET gate drive; actively held low when VCC is below turn-on threshold.
11 VC power_in Bias power supply input for output gate driver stage; requires bypass capacitor at least 10 times larger than main switch FET gate capacitance.
12 VCC power_in Power supply input operating from 12V to 28V with internal 34V clamp (30V absolute maximum from low impedance source); requires 0.1µF bypass capacitor to GROUND and additional bypass capacitor 10 times main switch FET gate capacitance.
13 NC unconnected Not connected.
14 VREF power_in 5V reference voltage output with ±2% accuracy providing error amplifier bias and oscillator charge current source up to ±20mA.

Key specifications

Parameter Value
Manufacturer Texas Instruments
Package SOIC-14
Category Power Management (PMIC)
Pins 14

CAD (KiCad official)

  • Symbol: UC3844D
  • Footprint: Package_SO:SOIC-14_3.9x8.7mm_P1.27mm
  • 3D model: SOIC-14 (KiCad packages3D, STEP)
  • 3D model files: uc3844d-etched.step / uc3844d-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); uc3844d.step / uc3844d.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 2026-10-07, 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 0.3, primary claude-haiku-4-5-20251001 (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