74HCT138D from Nexperia, 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	A0	input	Address input bit 0 (LSB). TTL-compatible input; selects one of eight outputs together with A1 and A2.
2	A1	input	Address input bit 1. TTL-compatible input; selects one of eight outputs together with A0 and A2.
3	A2	input	Address input bit 2 (MSB). TTL-compatible input; selects one of eight outputs together with A0 and A1.
4	E1	input	Enable input 1, active LOW. All outputs are HIGH unless E1 and E2 are LOW and E3 is HIGH.
5	E2	input	Enable input 2, active LOW. All outputs are HIGH unless E1 and E2 are LOW and E3 is HIGH.
6	E3	input	Enable input 3, active HIGH. Must be HIGH (with E1, E2 LOW) to enable the decoder outputs.
7	Y7	output	Decoder output 7, active LOW. Driven LOW when A2=A1=A0=HIGH and the chip is enabled; otherwise HIGH.
8	GND	power_in	Ground reference (0 V).
9	Y6	output	Decoder output 6, active LOW. Driven LOW when A2=A1=HIGH, A0=LOW and the chip is enabled; otherwise HIGH.
10	Y5	output	Decoder output 5, active LOW. Driven LOW when A2=HIGH, A1=LOW, A0=HIGH and the chip is enabled; otherwise HIGH.
11	Y4	output	Decoder output 4, active LOW. Driven LOW when A2=HIGH, A1=A0=LOW and the chip is enabled; otherwise HIGH.
12	Y3	output	Decoder output 3, active LOW. Driven LOW when A2=LOW, A1=A0=HIGH and the chip is enabled; otherwise HIGH.
13	Y2	output	Decoder output 2, active LOW. Driven LOW when A2=LOW, A1=HIGH, A0=LOW and the chip is enabled; otherwise HIGH.
14	Y1	output	Decoder output 1, active LOW. Driven LOW when A2=A1=LOW, A0=HIGH and the chip is enabled; otherwise HIGH.
15	Y0	output	Decoder output 0, active LOW. Driven LOW when A2=A1=A0=LOW and the chip is enabled; otherwise HIGH.
16	VCC	power_in	Positive supply voltage. Recommended operating range 4.5 V to 5.5 V for 74HCT138; absolute maximum -0.5 V to +7 V.

Key specifications

Parameter	Value
Manufacturer	Nexperia
Package	SOIC-16
Category	Logic
Pins	16

Ordering variants

Same part, different packaging or reel option.

74HCT138DD
74HCT138DPW
74HCT138DBQ

CAD (KiCad official)

Symbol: 74HCT138D
Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
3D model: SOIC-16 (KiCad packages3D, STEP)

Provenance

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

Datasheet: Nexperia datasheet (15 pp, sha256 645120bc441507e9, 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