UC2843M from HGSEMI, in a SOP-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, brought out for loop compensation. External RC networks between COMP and VFB set the control-loop response.
2	VFB	input	Inverting input of the Error Amplifier (internal reference ~2.5V). Normally connected to the switching supply output through a resistor divider for output-voltage regulation.
3	ISENSE	input	Current-sense input. A voltage proportional to the switch/inductor current (from a sense resistor) is applied here; the PWM comparator terminates the output switch conduction when this pin reaches ~1.0V (internal 1V clamp).
4	RT/CT	passive	Oscillator timing pin. Oscillator frequency and maximum duty cycle are set by an external resistor RT from VREF to this pin, and a capacitor CT from this pin to GND. Typical operation up to 500 kHz.
5	GND	power_in	Combined control-circuitry and power ground return for the IC. Single-point ground for both signal path and the totem-pole output stage.
6	OUT	output	High-current totem-pole gate-drive output. Directly drives the gate of an external power MOSFET; peak source/sink currents up to 1 A. VOH ~13.5V and VOL ~0.08V at 20 mA.
7	VCC	power_in	Positive supply for the IC. Absolute max 30V (or Zener-clamped ~38V). UC2843/45 UVLO turn-on ~8.4V, turn-off ~7.6V; operating ICC ~13 mA, startup ~0.17 mA.
8	VREF	power_out	5.0V (±2%) trimmed reference output. Sources bias/charging current for the timing capacitor CT via RT; short-circuit current limited to ~-100 mA (typ).

Key specifications

Parameter	Value
Manufacturer	HGSEMI
Package	SOP-8
Category	PMIC
Pins	8

Ordering variants

Same part, different packaging or reel option.

UC2843MM
UC2843MM/TR
UC2843MN

CAD (KiCad official)

Symbol: UC2843M
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOP-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`uc2843m.step`	122 KB	You want the bare part, or you mark your own boards.
`uc2843m-etched.step`	1.9 MB	You want the part with `UC2843M` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 453 faces against 147 in the bare model. It survives export, section views, and rendering in any CAD tool, and it drops straight into KiCad or Fusion with no extra setup.

Provenance

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

Datasheet: HGSEMI datasheet (12 pp, sha256 b372c24e6b8779f6, 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