UC1843AMDREP from Texas Instruments, in a SOIC-8. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	COMP	output	Error amplifier output / compensation node. Connect frequency-compensation network between this pin and VFB. Also serves as the control-loop input to the PWM comparator.
2	VFB	input	Inverting input to the error amplifier. Normally connected via a resistor divider to the converter output; the non-inverting input is internally tied to the 2.50 V reference. Absolute max input range -0.3 V to 6.3 V.
3	ISENSE	input	Current-sense input to the PWM current-sense comparator. Internal 1 V clamp provides pulse-by-pulse current limiting. Typical gain 3 V/V; input bias current ~-2 uA; absolute max range -0.3 V to 6.3 V.
4	RT/CT	passive	Oscillator timing pin. Connect a timing resistor from VREF to RT/CT and a timing capacitor from RT/CT to GND to set the switching frequency (up to 500 kHz). Oscillator discharge current trimmed to ~8.3 mA.
5	GND	power_in	Device ground / power ground return. All internal reference voltages are referenced to this pin.
6	OUTPUT	output	High-current totem-pole gate-drive output for driving an external power MOSFET. Rated for +/-1 A peak; typical rise/fall time 50 ns into 1 nF load; high-level output 13.5 V typical with 20 mA source.
7	VCC	power_in	Positive supply input for the IC and output driver. UVLO start threshold 8.4 V typ, turn-off 7.6 V typ (UC1843A). Low start-up current <0.5 mA. Internal 34 V zener clamp; absolute max low-impedance source 30 V.
8	VREF	power_out	Trimmed 5.0 V internal bandgap reference output, capable of sourcing up to 50 mA. Typically used to bias the oscillator timing network and external circuitry.

Key specifications

Parameter	Value
Manufacturer	Texas Instruments
Package	SOIC-8
Category	PMIC
Pins	8

Ordering variants

Same part, different packaging or reel option.

UC1843AMDREP

CAD (KiCad official)

Symbol: UC1843AMDREP
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8 (KiCad packages3D, STEP)

Provenance

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

Datasheet: Texas Instruments datasheet (17 pp, sha256 53c59033a3dd0a96, retrieved 2026-08-17, tier: lcsc)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF