VPC28C45 from VPSC, 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 compensation output. External compensation network (typ. RC to FB) is connected here to shape the loop response and set zero/pole placement. Internal current limit means the user can override COMP by pulling it to GND to force zero duty cycle.
2	FB	input	Inverting input of the internal error amplifier. Regulated to VFB = 2.5V (typ). Used for closing the voltage-mode feedback loop from the power converter's output.
3	CS	input	Current-sense input. Connect to the primary-side current-sense resistor; PWM terminates OUT when VCS reaches the current-limit threshold (VCS_th ≈ 1V max). Can also be used for voltage-mode configuration by injecting a ramp.
4	RT/CT	passive	Oscillator frequency programming pin. Connect timing resistor RT from VREF to this pin and timing capacitor CT from this pin to GND to set the switching frequency: fOSC ≈ 1.6/(RT·CT). Use RT ≥ 5kΩ. Route CT ground return directly to GND with a short trace.
5	GND	power_in	Analog ground. Serves as both signal and power ground return for this package (no separate PGND pin).
6	OUT	output	Gate-driver output for the external N-channel MOSFET. Totem-pole PMOS/NMOS stage sources and sinks up to 1A peak. OUT is held low when VDD is below the UVLO turn-on threshold. Rise ≈ 30ns, fall ≈ 20ns into 1nF.
7	VDD	power_in	Bias supply input. Absolute max 30V; internal clamp starts conducting around 19V and reaches 24.7V/14mA. UVLO turn-on 14.6V (typ) and turn-off 8.7V (typ) for VPC28C44. Bypass with ≥0.1µF close to the pin plus a larger bulk capacitor (≥10× the driven MOSFET gate capacitance).
8	VREF	power_out	5V (±1%) internal reference output. Sources up to 20mA and supplies the RT charging current for the oscillator. Requires a ≥0.1µF ceramic bypass capacitor to GND placed as close to the pin as possible for stability.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

VPC28C44
VPC28C45VPC38C44

CAD (KiCad official)

Symbol: VPC28C45
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOP-8 (KiCad packages3D, STEP)

Provenance

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

Datasheet: VPSC datasheet (15 pp, sha256 41de8f28b106ea3c, retrieved 2026-08-17, 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: 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