UM3212M8 from Union Semiconductor, in a MSOP-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	GND	power_in	Ground (0V) reference for the device.
2	VREF1	power_in	Low-voltage side reference supply voltage for SCL1 and SDA1. Operating range 0V to 5V; typical 1.0V to 3.6V.
3	SCL1	bidirectional	Serial clock, low-voltage side. Open-drain I2C bus I/O; connect to VREF1 through a pull-up resistor.
4	SDA1	bidirectional	Serial data, low-voltage side. Open-drain I2C bus I/O; connect to VREF1 through a pull-up resistor.
5	SDA2	bidirectional	Serial data, high-voltage side. Open-drain I2C bus I/O; connect to VREF2 through a pull-up resistor.
6	SCL2	bidirectional	Serial clock, high-voltage side. Open-drain I2C bus I/O; connect to VREF2 through a pull-up resistor.
7	VREF2	power_in	High-voltage side reference supply voltage for SCL2 and SDA2. Operating range 0V to 5V; typical 1.8V to 5.5V.
8	EN	input	Switch enable input. When HIGH the translator is on and the SCL1/SDA1 pins are connected to SCL2/SDA2; when LOW all channels are high-impedance. Connect to VREF2 and pull up through a high-value resistor.

Key specifications

Parameter	Value
Manufacturer	Union Semiconductor
Package	MSOP-8
Category	Logic
Pins	8

Ordering variants

Same part, different packaging or reel option.

UM3212M8
UM3212DA
UM3212V8

CAD (KiCad official)

Symbol: UM3212M8
Footprint: Package_SO:MSOP-8_3x3mm_P0.65mm
3D model: MSOP-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`um3212m8.step`	123 KB	You want the bare part, or you mark your own boards.
`um3212m8-etched.step`	2.0 MB	You want the part with `UM3212M8` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 481 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: Union Semiconductor datasheet (13 pp, sha256 2a269d25929ecc53, 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