UC2844BM from HGSEMI, in a SOP-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	bidirectional	Error amplifier compensation pin, used to compensate the error amplifier feedback network.
2	VFB	input	Error amplifier inverting input; the recommended input voltage range for VFB is 0 to 5.0 V.
3	ISENSE	input	Current-sense comparator input; the recommended input voltage range is 0 to 5.0 V, and the peak sense signal is limited to 1.0 V at the 1 V maximum input signal.
4	RT/CT	bidirectional	RC oscillator timing pin, with recommended input voltage range 0 to 5.0 V and oscillation frequency range 100 to 500 kHz.
5	GND	power_in	Power ground; bypass capacitors should be placed close to this pin to handle high peak currents when driving capacitive loads.
6	OUTPUT	output	PWM totem-pole output for driving an N-channel MOSFET, rated at ±1 A peak output current and limited to 200 mA average output current, held low when off.
7	VCC	power_in	Supply pin with a recommended maximum of 28 V, an absolute maximum of 30 V, and a maximum supply current of 25 mA.
8	VREF	power_in	Internally trimmed 5.0 V reference output (4.95 to 5.05 V at 25°C, 1 mA load) with a reference output current limit of -20 mA.

Key specifications

Parameter	Value
Manufacturer	HGSEMI
Package	SOP-8
Category	Power Management (PMIC)
Pins	8

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter	Symbol	Min	Typ	Max	Unit	Conditions	Page
Supply voltage	VCC			28	V		3
Input voltage (RT/CT, VFB, ISENSE)	VI	0		5	V		3
Output voltage	VO	0		28	V		3
Supply current	ICC			25	mA		3
Average output current	Io			200	mA		3
Reference output current	Io(ref)			-20	mA		3
Oscillation frequency	fosc		100	500	kHz		3
Ambient operating temperature	Ta	-40		105	°C		3
Junction operating temperature	TJ			125	°C		3
Supply voltage	Vcc			30	V		3
Output current	Io	-1		1	A		3
Analog input (pins 2, 3)	VI(ANA)	-0.3		5.5	V		3
Error amplifier output sink current	ISINK(EA)			10	mA		3
Power dissipation	PD			850	mW	Tamb≤25°C	3
Junction-to-ambient thermal resistance	RthJA			143	°C/W		3
Junction-to-case (top) thermal resistance	RthJC			47.6	°C/W		3
Junction temperature	TJ			150	°C		3
Storage temperature	Tstg	-65		150	°C		3
Latch-up current	LU			100	mA	25°C&125°C	3
ESD human body model	ESD-HBM	-2000		2000	V	25°C	3
ESD charged device model	ESD-CDM	-500		500	V	25°C	3
Lead temperature (soldering 10 s)	TLEAD			260	°C	焊接 10s	3
Reference output voltage	VREF	4.95	5	5.05	V	Ta = 25°C, IL = 1mA	4
Line regulation	ΔVREF1		6	20	mV	VCC=12V~25V	4
Load regulation	ΔVREF2		6	25	mV	IL=1 mA ~20 mA	4
Temperature stability	TS		0.2	0.4	mV/°C		4
Total output variation (line, load, temp)	ΔVREF3	4.82		5.18	V	Line, Load, Temp	4
Long-term stability	S		5	25	mV	Ta = 25°C，1000 小时	4
Output short-circuit current	ISC	-30	-100	-180	mA	VREF=0V, Ta=25°C	4
Initial oscillator accuracy	f	49	52	55	kHz	Ta=25°C	4
Oscillator voltage stability	Δf/ΔVCC		0.2	1	%	VCC=12V~25V	4
Discharge current	Idischg	7.5		8.8	mA	VOSC = 2V	4
Error amplifier input voltage	VI(EA)	2.42	2.5	2.58	V	Vpin1=2.5V	4
Error amplifier input bias current	IBIAS		-0.1	-2	µA		4
Open-loop voltage gain	AVOL	60	90		dB	2 ≤Vo≤4V	4
Unity-gain bandwidth	BW	0.7	1		MHz	Ta=25°C	4
Error amplifier power supply rejection ratio	PSRR	60	70		dB	12≤Vcc≤25V	4
Error amplifier output sink current	Isink	2	12		mA	Vpin2=2.7V, Vpin1=1.1V	4
Error amplifier output source current	Isource	-0.5	-1		mA	Vpin2=2.3V, Vpin1=5V	4
Error amplifier output high voltage	VOH	5	6.2		V	Vpin2=2.3V, RL=15kΩ to GND	4
Error amplifier output low voltage	VOL		0.8	1.1	V	Vpin2=2.7V, RL=15kΩ to VREF	4
Current-sense gain	GV	2.85	3	3.15	V/V	note 1, 2	4
Maximum input signal	VI(MAX)	0.9	1	1.1	V	Vpin1=5V (note 1)	4
Current-sense input bias current	IBIAS		-2	-10	µA		4
Output delay	TPLH		150	300	ns	Vpin3=0 to 2V	4
Output low voltage at Isink=20mA	VOL		0.1	0.4	V	Isink=20mA	4
Output low voltage at Isink=200mA	VOL		1.6	2.2	V	Isink=200mA	4
Output high voltage at Isource=20mA	VOH	13	13.5		V	Isource=20mA	4
Output high voltage at Isource=200mA	VOH	12	13.5		V	Isource=200mA	4
Rise time	tR		50	150	ns	Ta=25°C, CL=1nF	4
Fall time	tF		50	150	ns	Ta=25°C, CL=1nF	4
UVLO low-level output saturation voltage	VOL(UVLO)		0.7	1.2	V	Vcc=5V, Isink=1mA	5
Start-up threshold	VTH(ST)	15	16	17	V		5
Minimum operating voltage after turn-on	VOPR(min)	9	10	11	V		5
Minimum duty cycle	D(MIN)			0	%		5
Maximum duty cycle	D(MAX)	47	48	50	%		5
Start-up current	IST		0.3	0.5	mA		5
Operating current	ICC(opr)		12	17	mA	Vpin2=Vpin3=0V	5
Vcc zener voltage	Vz	30	34		V	Icc=25mA	5

CAD (KiCad official)

Symbol: UC2844BM
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOP-8 (KiCad packages3D, STEP)
3D model files: uc2844bm-etched.step / uc2844bm-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); uc2844bm.step / uc2844bm.glb are the bare package body.

Provenance

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

Datasheet: HGSEMI datasheet (11 pp, sha256 27f143cab0a30a5f, retrieved 2026-11-05, 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-5-5 (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).

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UC2844BM

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