KP2126SGA from Kiwi Instruments, 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	VDD	power_in	Chip supply pin. Recommended operating range 11-27V; VDD_ON typ 16.3V, VDD_OFF typ 9V; VDD_OVP typ 30V; VDD clamp typ 34.5V at 7mA. Startup current typ 2µA, operating current typ 0.7mA.
2	GND	power_in	Chip ground reference pin.
3	FB	input	System feedback pin. Auxiliary winding voltage is divided by resistors and fed into FB for CV output-voltage regulation and CC output-current regulation. Internal EA reference VFBREF typ 2.0V; short-circuit threshold 0.7V (10ms debounce); demag comparator threshold 20mV. Absolute max −0.7 to 7V.
4	CS	input	Current-sense input pin. Senses primary-side current via a sense resistor for peak-current control and cycle-by-cycle OCP; VCS(max) typ 500mV, leading-edge blanking 500ns, OC turn-off delay 100ns. Absolute max −0.3 to 7V.
5	Drain	power_in	Drain of the internal 650V power MOSFET (Rdson typ 1.6Ω, ID 5A). Pins 5-8 are internally tied together for improved thermal dissipation; connect to the transformer primary switching node.
6	Drain	power_in	Drain of the internal 650V power MOSFET. Pins 5-8 are tied together internally for thermal dissipation.
7	Drain	power_in	Drain of the internal 650V power MOSFET. Pins 5-8 are tied together internally for thermal dissipation.
8	Drain	power_in	Drain of the internal 650V power MOSFET. Pins 5-8 are tied together internally for thermal dissipation.

Key specifications

Parameter	Value
Manufacturer	Kiwi Instruments
Package	SOP-8
Category	PMIC
Pins	8

Ordering variants

Same part, different packaging or reel option.

KP2126SGA
KP2126SGADP

CAD (KiCad official)

Symbol: KP2126SGA
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
`kp2126sga.step`	122 KB	You want the bare part, or you mark your own boards.
`kp2126sga-etched.step`	2.0 MB	You want the part with `KP2126SGA` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 495 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: Kiwi Instruments datasheet (8 pp, sha256 1c293099a61e2bb9, 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