ST26C31BDR from STMicroelectronics, in a SOIC-16. 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	AIN	input	Channel A TTL/CMOS single-ended input. VIH >= 2 V, VIL <= 0.8 V. Drives the channel A differential output pair (AOUT / /AOUT).
2	AOUT	output	Channel A non-inverting differential (RS-422) output. 3-state; high impedance when enable inputs disable the driver. Drives balanced line loads (RL = 100 Ω typical).
3	/AOUT	output	Channel A inverting differential (RS-422) output (complement of AOUT). 3-state; high impedance when enable inputs disable the driver.
4	EN	input	Active-high enable input. Together with /EN (pin 12) enables all four channel outputs. When EN = L and /EN = H, all outputs are placed in high-impedance (Z) state.
5	/BOUT	output	Channel B inverting differential (RS-422) output (complement of BOUT). 3-state; high impedance when the driver is disabled.
6	BOUT	output	Channel B non-inverting differential (RS-422) output. 3-state; high impedance when the driver is disabled.
7	BIN	input	Channel B TTL/CMOS single-ended input. VIH >= 2 V, VIL <= 0.8 V. Drives the channel B differential output pair.
8	GND	power_in	Device ground reference (0 V). Common return for VCC and all I/O.
9	CIN	input	Channel C TTL/CMOS single-ended input. VIH >= 2 V, VIL <= 0.8 V. Drives the channel C differential output pair.
10	COUT	output	Channel C non-inverting differential (RS-422) output. 3-state; high impedance when the driver is disabled.
11	/COUT	output	Channel C inverting differential (RS-422) output (complement of COUT). 3-state; high impedance when the driver is disabled.
12	/EN	input	Active-low enable input. Together with EN (pin 4) enables all four channel outputs. When EN = L and /EN = H, all outputs are placed in high-impedance (Z) state.
13	/DOUT	output	Channel D inverting differential (RS-422) output (complement of DOUT). 3-state; high impedance when the driver is disabled.
14	DOUT	output	Channel D non-inverting differential (RS-422) output. 3-state; high impedance when the driver is disabled.
15	DIN	input	Channel D TTL/CMOS single-ended input. VIH >= 2 V, VIL <= 0.8 V. Drives the channel D differential output pair.
16	VCC	power_in	Positive supply voltage. Recommended 4.5 to 5.5 V (nominal 5 V); absolute max 7 V. Typical quiescent supply current 200 µA (max 500 µA) with static inputs.

Key specifications

Parameter	Value
Manufacturer	STMicroelectronics
Package	SOIC-16
Category	Interface
Pins	16

Ordering variants

Same part, different packaging or reel option.

ST26C31BDR
ST26C31BN
ST26C31BTR

CAD (KiCad official)

Symbol: ST26C31BDR
Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
3D model: SOIC-16 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`st26c31bdr.step`	217 KB	You want the bare part, or you mark your own boards.
`st26c31bdr-etched.step`	2.8 MB	You want the part with `ST26C31BDR` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 674 faces against 267 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: STMicroelectronics datasheet (15 pp, sha256 628b38556e56079d, retrieved 2026-08-17, tier: manufacturer)
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