CH552E from WCH Jiangsu Qin Heng, in a MSOP-10. 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	P1.4/T2_/CAP1_/SCS/TIN2/UCC1/AIN1	bidirectional	Port 1 bit 4 general-purpose I/O with internal pull-up by default. Muxed alternate functions: Timer 2 external count input (T2_ inverted mapping), Timer 2 capture 1 input (CAP1_), SPI0 slave chip-select (SCS), Touch-Key channel TIN2 input, USB type-C configuration channel UCC1, and ADC channel AIN1 analog input.
2	P1.5/MOSI/PWM1/TIN3/UCC2/AIN2	bidirectional	Port 1 bit 5 general-purpose I/O with internal pull-up by default. Muxed alternate functions: SPI0 MOSI (master output / slave input), PWM1 output, Touch-Key channel TIN3, USB type-C configuration channel UCC2, and ADC channel AIN2 analog input.
3	P1.6/MISO/RXD1/TIN4	bidirectional	Port 1 bit 6 general-purpose I/O with internal pull-up by default. Muxed alternate functions: SPI0 MISO (master input / slave output), UART1 serial data receive (RXD1), and Touch-Key channel TIN4.
4	P1.7/SCK/TXD1/TIN5	bidirectional	Port 1 bit 7 general-purpose I/O with internal pull-up by default. Muxed alternate functions: SPI0 serial clock (SCK), UART1 serial data transmit (TXD1), and Touch-Key channel TIN5.
5	RST/T2EX/CAP2_	input	External reset input, active high. Internal pull-down resistor on RST. Alternate functions: Timer 2 reload / capture trigger input (T2EX) and Timer 2 capture 2 input (CAP2_ alternate mapping).
6	P3.6/UDP	bidirectional	Port 3 bit 6 general-purpose I/O; alternate function is the USB D+ (UDP) signal. When used as USB, no external series resistor is allowed. P3.6 uses V33 as its I/O supply, so digital high level is limited to V33 and does not support 5V logic.
7	P3.7/UDM	bidirectional	Port 3 bit 7 general-purpose I/O; alternate function is the USB D− (UDM) signal. When used as USB, no external series resistor is allowed. P3.7 uses V33 as its I/O supply, so digital high level is limited to V33 and does not support 5V logic.
8	GND	power_in	Common ground (VSS) return for the chip.
9	VCC	power_in	Main power supply input (VDD), 3.3 V or 5 V. Requires an external 0.1 µF decoupling capacitor to GND placed close to the pin.
10	V33	power_in	Internal USB LDO regulator output and internal USB supply input. When VCC < 3.6 V, tie V33 to VCC externally. When VCC > 3.6 V (5 V operation), connect a 0.1 µF decoupling capacitor from V33 to GND and let the internal LDO produce 3.3 V.

Key specifications

Parameter	Value
Manufacturer	WCH Jiangsu Qin Heng
Package	MSOP-10
Category	MCU
Pins	10

Ordering variants

Same part, different packaging or reel option.

CH552E
CH552T
CH552G
CH552P

CAD (KiCad official)

Symbol: CH552E
Footprint: Package_SO:MSOP-10_3x3mm_P0.5mm
3D model: MSOP-10 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`ch552e.step`	148 KB	You want the bare part, or you mark your own boards.
`ch552e-etched.step`	1.6 MB	You want the part with `CH552E` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 389 faces against 177 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: WCH Jiangsu Qin Heng datasheet (53 pp, sha256 b3995c47a6c00a9f, 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