SIT1044QT from SIT, 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	TXD	input	Transmit data input from the CAN controller. A low level on TXD drives the bus dominant; a high level (or floating) leaves the bus recessive. Internally biased to VIO via a pull-up so an open input defaults to recessive.
2	GND	power_in	Device ground reference for VCC and all internal circuitry. Return path for CAN bus and MCU-side signals.
3	VCC	power_in	5 V supply for the transceiver core and CAN bus driver stage. Operating range 4.75 V to 5.25 V; absolute maximum -0.3 V to +7 V. Decouple locally to GND.
4	RXD	output	Receive data output to the CAN controller. Reports the state of the CAN bus: low = dominant, high = recessive. Output levels are referenced to VIO (or VCC on non-VIO variants).
5	N.C.	unconnected	No internal connection on the SIT1044QT / SIT1044QTK / SIT1044QT/1 / SIT1044QTK/1 variants. On SIT1044QT/3, /31, /QTK/3, /QTK/31 this pin is repurposed as VIO - the pinout is otherwise identical.
6	CANL	bidirectional	Low-side CAN bus input/output. Together with CANH forms the differential CAN pair. Rated for -40 V to +40 V bus fault voltage and short-circuit protected (±100 mA).
7	CANH	bidirectional	High-side CAN bus input/output. Together with CANL forms the differential CAN pair. Rated for -40 V to +40 V bus fault voltage and short-circuit protected (±100 mA).
8	STB	input	Mode select input. Low = high-speed (normal) mode; high = low-power standby mode with remote wake-up detection. Internally pulled up to VIO so an open pin defaults to standby.

Key specifications

Parameter	Value
Manufacturer	SIT
Package	SOP-8
Category	Comm/UART
Pins	8

Ordering variants

Same part, different packaging or reel option.

SIT1044QT
SIT1044QT/1
SIT1044QT/3
SIT1044QT/31
SIT1044QTK
SIT1044QTK/1
SIT1044QTK/3
SIT1044QTK/31

CAD (KiCad official)

Symbol: SIT1044QT
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
`sit1044qt.step`	122 KB	You want the bare part, or you mark your own boards.
`sit1044qt-etched.step`	1.7 MB	You want the part with `SIT1044QT` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 445 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: SIT datasheet (22 pp, sha256 5e62b1aa456e113b, 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