TMCS1108A3UQDR from Texas Instruments, in a SOIC-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	IN+	passive	Positive current input pin. Tied to pin 2 to form the primary current path through the internal 1.8mΩ conductor. Current flows from IN+ to IN- for positive sensed current.
2	IN+	passive	Positive current input pin (duplicate of pin 1). Both IN+ pins connect internally to the same primary conductor and must be paralleled externally.
3	IN-	passive	Negative current input pin. Tied to pin 4 to form the return of the primary current path.
4	IN-	passive	Negative current input pin (duplicate of pin 3). Both IN- pins connect internally to the same primary conductor and must be paralleled externally.
5	GND	power_in	Device ground reference for the secondary (isolated) side. All secondary-side voltages (VS, VOUT) are referenced to this pin.
6	NC	unconnected	No internal connection. Pin may tolerate capacitive or resistive connection to GND or VS; recommended to short to GND if allowed.
7	VOUT	output	Analog output voltage proportional to the sensed input current. Zero-current output is 0.5×VS (bidirectional B-suffix) or 0.1×VS (unidirectional U-suffix); sensitivity for A3 variant is 200 mV/A.
8	VS	power_in	Device power supply. Operating range 3V to 5.5V for A1/A2/A3 variants (4.5V to 5.5V for A4 variant). Quiescent current 6mA max. Bypass with a local decoupling capacitor to GND.

Key specifications

Parameter	Value
Manufacturer	Texas Instruments
Package	SOIC-8
Category	Sensor
Pins	8

Ordering variants

Same part, different packaging or reel option.

TMCS1108A1BQDR
TMCS1108A2BQDR
TMCS1108A3BQDR
TMCS1108A4BQDR
TMCS1108A1UQDR
TMCS1108A2UQDR
TMCS1108A3UQDR
TMCS1108A4UQDR

CAD (KiCad official)

Symbol: TMCS1108A3UQDR
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`tmcs1108a3uqdr.step`	122 KB	You want the bare part, or you mark your own boards.
`tmcs1108a3uqdr-etched.step`	3.0 MB	You want the part with `TMCS1108A3UQDR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 713 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: Texas Instruments datasheet (43 pp, sha256 86a2cf7b17bcf7bf, retrieved 2026-08-17, tier: manufacturer)
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