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Contents

README

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UCC2891DR

Texas Instruments · AC-DC Controllers And Regulators · SOIC-16

UCC2891DR from Texas Instruments, in a SOIC-16. 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 RTDEL input A resistor from this pin to GND programs the turn-on delay for both gate drive outputs to accommodate the resonant transitions of the active clamp power converter.
2 RTON input A resistor to GND programs an internal current source that charges the internal timing capacitor and is used to set the operating frequency and maximum duty cycle.
3 RTOFF input A resistor to GND programs an internal current source that discharges the internal timing capacitor and is used to set the switching period and maximum duty cycle.
4 VREF power_out Supplies the controller's internal 5-V bias rail as a reference voltage with current-limited output of approximately 5 mA for external circuits.
5 SYNC input Unidirectional synchronization input for the internal oscillator with minimum pulse width of approximately 50 ns and synchronizing frequency higher than the free-running oscillator frequency.
6 GND power_in Provides the reference potential for all small-signal control and programming circuitry inside the device.
7 CS input Direct input to the PWM and current-limit comparators for peak current sensing; threshold is 0.75 V for UCC2891.
8 RSLOPE input A resistor connected from this pin to GND sets the amplitude of the slope compensation current for current-mode control circuitry.
9 FB input Input for the control voltage of the pulse width modulator generated by an external error amplifier; useful voltage range is approximately 1.25 V to 4.5 V.
10 SS/SD input A capacitor from this pin to GND is charged by an internal current source to program the soft-start interval and discharged during fault conditions.
11 PGND power_in Dedicated connection for all high-current circuits including the two high-current gate drivers; requires low-impedance external connection to GND pin.
12 AUX output High-current gate drive output for the auxiliary clamp MOSFET with 2-A source and 2-A sink current capability; active low for P-channel devices.
13 OUT output High-current output driving the main N-channel PWM switching MOSFET with 2-A source and 2-A sink current capability.
14 VDD power_in Power supply for the device biasing the internal gate drivers and 5-V regulator; supply range is 8.5 to 16.0 V with recommended 1-µF bypass capacitor to PGND.
15 LINEUV input Monitors incoming power source to provide accurate undervoltage lockout with programmable hysteresis; threshold voltage is 1.27 V.
16 VIN power_in Connected to the input power rail directly for UCC2891; a high-voltage P-channel JFET startup device provides startup current until bootstrap bias is available, maximum rating 120 V.

Key specifications

Parameter Value
Manufacturer Texas Instruments
Package SOIC-16
Category Power Management (PMIC)
Pins 16

CAD (KiCad official)

  • Symbol: UCC2891DR
  • Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
  • 3D model: SOIC-16 (KiCad packages3D, STEP)
  • 3D model files: ucc2891dr-etched.step / ucc2891dr-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); ucc2891dr.step / ucc2891dr.glb are the bare package body.

Provenance

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

  • Datasheet: Texas Instruments datasheet (41 pp, sha256 0b123b68deef52c5, retrieved 2026-09-26, tier: manufacturer)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.2, primary claude-haiku-4-5-20251001 (text), consensus claude-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).

Datasheet PDF