SIT1027QT 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	RXD	output	Receive data output to the MCU (open-drain, needs external pull-up). Reports the state of the LIN bus; also driven active LOW after a remote wake-up event to interrupt the microcontroller.
2	SLP_N	input	Sleep control input (active LOW). Controls the inhibit output and mode transitions: hold HIGH for tgotonorm to enter Normal mode, hold LOW for tgotosleep to enter Sleep mode. Also resets the wake-up source flag on TXD and wake-up request on RXD. Has an internal pull-down so a floating pin forces Sleep mode.
3	n.c.	unconnected	Not connected. Leave open (or tie to a convenient net per PCB preference).
4	TXD	input	Transmit data input from the MCU. LOW drives the LIN bus to the dominant state, HIGH releases it to the recessive state. Has an internal pull-down to GND so an unconnected TXD forces a defined level.
5	GND	power_in	Ground reference for the device.
6	LIN	bidirectional	LIN bus line I/O (single-wire, up to 20 kBd, 12V nominal). Includes an integrated ~30 kΩ pull-up to VBAT for slave-node operation; when used as a master node, an additional external pull-up (typically 1 kΩ) to VBAT through a series diode is required.
7	VBAT	power_in	Battery supply voltage input. Operating range 5.5V to 27V (12V automotive nominal). Undervoltage detection disables the driver below Vth(VBATL)L and re-enables above Vth(VBATL)H.
8	n.c.	unconnected	Not connected.

Key specifications

Parameter	Value
Manufacturer	SIT
Package	SOP-8
Category	Interface
Pins	8

Ordering variants

Same part, different packaging or reel option.

SIT1027QT
SIT1027QTK

CAD (KiCad official)

Symbol: SIT1027QT
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOP-8 (KiCad packages3D, STEP)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: SIT datasheet (20 pp, sha256 554c411d0b8bbe3b, 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