SG3525M from HGSEMI, in a SOP-16. 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	Inv. Input	input	Inverting input of the internal error amplifier. Typical input offset 1.5mV, bias current ~1µA, common-mode range up to VREF (5.1V). Used with the compensation pin to close the voltage-regulation loop.
2	Noninv. Input	input	Non-inverting input of the internal error amplifier. Common-mode range 1.5V to 5.2V, allowing direct connection to the on-chip 5.1V reference without an external divider.
3	Sync	bidirectional	Oscillator sync pin. Used to synchronize the internal oscillator to an external clock (threshold 1.2-2.8V, sink ~1.3mA at 3.5V) or to slave/master multiple SG3525s together.
4	OSC. Output	output	Oscillator clock output. Delivers a ~4V, 0.6µs-wide clock pulse per cycle, used for scope monitoring or as a sync source for downstream stages.
5	CT	passive	Timing capacitor pin. Connect CT to GND to set the oscillator frequency together with RT (e.g. RT=2kΩ, CT=470pF → ~400kHz; RT=200kΩ, CT=0.1µF → ~60Hz).
6	RT	passive	Timing resistor pin. Connect RT to GND to program the oscillator charging current (charging current up to 5mA) and hence frequency, in conjunction with CT.
7	Discharge	passive	CT discharge pin. A resistor placed between CT (pin 5) and Discharge sets the dead-time (blanking) between Output A and Output B pulses.
8	Soft-Start	passive	Soft-start capacitor pin. A ~50µA (typ 51µA, 25-80µA) internal source charges an external cap here to slowly ramp the PWM duty cycle at start-up; discharged low (<0.7V) during shutdown.
9	Compensation	output	Error-amplifier output / PWM comparator input. External RC network from this pin sets the loop compensation. PWM zero duty at ~0.9V, max duty (≥45%) at ~3.2V.
10	Shutdown	input	Active-high shutdown input. Driving this pin above ~0.8V (threshold 0.6-1.0V) inhibits both outputs and discharges the soft-start cap, providing pulse-by-pulse current limit or emergency shutdown. Input current ~0.3mA at 2.5V.
11	Output A	output	Totem-pole PWM output A. Sources/sinks >150mA (peak 400mA); VOH ≥18V at 20mA source, VOL ≤0.4V at 20mA sink. Alternates with Output B at half the oscillator frequency for push-pull/bridge drive.
12	Ground	power_in	Signal / logic ground return for the reference, oscillator and control circuitry. Tie to system ground; often decoupled separately from the VC power ground in switching supplies.
13	VC	power_in	Collector supply for the output totem-pole drivers. Absolute max 40V; usually tied to VCC or a separate driver rail sized for the gate-drive current (>150mA continuous).
14	Output B	output	Totem-pole PWM output B, complementary to Output A. Same drive characteristics (>150mA source/sink, 400mA peak). NOR-gated logic guarantees a low ('off') level during dead-time or shutdown.
15	VCC	power_in	Main chip supply. Operating range 8-35V with UVLO threshold ~7V (6-8V). Typical ICC 12mA, max 20mA at 35V. Decouple locally with 0.1µF.
16	Vref	power_out	Internal 5.1V ±1% reference output. Sources up to 20mA (short-circuit ~80mA). Decouple with 0.1µF to GND; can be used as bias for the error-amp non-inverting input.

Key specifications

Parameter	Value
Manufacturer	HGSEMI
Package	SOP-16
Category	PMIC
Pins	16

Ordering variants

Same part, different packaging or reel option.

SG3525MM/TR
SG3525MN
SG3525MMT/TR
SG3525MMS/TR

CAD (KiCad official)

Symbol: SG3525M
Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
3D model: SOP-16 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`sg3525m.step`	217 KB	You want the bare part, or you mark your own boards.
`sg3525m-etched.step`	2.3 MB	You want the part with `SG3525M` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 570 faces against 267 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 (9 pp, sha256 5277772c8ab62d7b, 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