EG1253 from EG Micro, 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	FB	input	Feedback pin. PWM duty cycle is determined by the voltage on this pin combined with the current-sense signal. FB open-circuit voltage ~5.3 V; burst-mode threshold ~1.5 V; overload threshold Vth_OLP ~4.6 V.
2	NC	unconnected	No connection (悬空). Leave floating.
3	CS	input	Current-sense input. Senses voltage across the CS resistor to implement cycle-by-cycle over-current protection. Current-limit threshold Vcs(max) ≈ 0.9 V; internal 250 ns leading-edge blanking; OCP delay ~120 ns.
4	RI	passive	Oscillator frequency-setting pin. An external resistor to GND sets the PWM switching frequency by Fosc(kHz) = 3640 / RI(kΩ). Typical Fosc = 65 kHz with RI = 56 kΩ; RI open-pin voltage ~2 V.
5	GND	power_in	Chip ground reference for all internal circuitry and the gate driver return.
6	OUT	output	Gate-drive output for the external power MOSFET. Voh ≥ 11 V at Isource = 20 mA; Vol ≤ 0.3 V at Isink = -20 mA; typical rise/fall 130 ns / 50 ns into 1 nF. Maximum duty cycle Dmax ≈ 46% (50% max).
7	VCC	power_in	Chip supply. UVLO turn-on ~16 V, turn-off ~10.5 V; VOP over-voltage protection ~28.2 V (on) / 27 V (off); internal Zener clamp ~32 V at 10 mA. Startup current ~6 µA, operating current ~2.3 mA.
8	RT	input	Over-temperature protection pin. An external NTC thermistor to GND sets the OTP trip point. Internal 80 µA current source biases the pin; OTP triggers when V(RT) falls to ~1.0 V and clears when V(RT) rises above ~1.1 V.

Key specifications

Parameter	Value
Manufacturer	EG Micro
Package	SOP-8
Category	PMIC
Pins	8

CAD (KiCad official)

Symbol: EG1253
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
`eg1253.step`	122 KB	You want the bare part, or you mark your own boards.
`eg1253-etched.step`	1.5 MB	You want the part with `EG1253` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 383 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: EG Micro datasheet (11 pp, sha256 4e175864533cd6be, 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