SN75ALS191DR 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	VCC	power_in	5V power supply positive terminal (VCC, 4.75V-5.25V). Typical supply current ICC = 32 mA (all drivers, no load).
2	1A	input	Single-ended TTL/CMOS data input for differential driver channel 1. VIH ≥ 2V, VIL ≤ 0.8V.
3	2A	input	Single-ended TTL/CMOS data input for differential driver channel 2. VIH ≥ 2V, VIL ≤ 0.8V.
4	GND	power_in	Device ground reference terminal.
5	2Z	output	Inverting differential output for channel 2 (ANSI EIA/TIA-422-B compliant). IOH = -50 mA, IOL = 50 mA;
6	2Y	output	Non-inverting differential output for channel 2 (ANSI EIA/TIA-422-B compliant). IOH = -50 mA, IOL = 50 mA;
7	1Z	output	Inverting differential output for channel 1 (ANSI EIA/TIA-422-B compliant). IOH = -50 mA, IOL = 50 mA;
8	1Y	output	Non-inverting differential output for channel 1 (ANSI EIA/TIA-422-B compliant). IOH = -50 mA, IOL = 50 mA;

Key specifications

Parameter	Value
Manufacturer	Texas Instruments
Package	SOIC-8
Category	Comm/UART
Pins	8

Ordering variants

Same part, different packaging or reel option.

SN75ALS191DRD
SN75ALS191DR
SN75ALS191DRP
SN75ALS191DRN
SN75ALS191DRPS

CAD (KiCad official)

Symbol: SN75ALS191DR
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOIC-8 (KiCad packages3D, STEP)

Provenance

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

Datasheet: Texas Instruments datasheet (20 pp, sha256 d75efd66a05d6ce1, 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