74HC139M from HGSEMI, in a SOP-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	SELECTa	input	Active-low select/enable input for decoder A. When low, outputs Y0a-Y3a follow the A0a/A1a address inputs. When high, all outputs of decoder A are forced high.
2	A0a	input	Address input bit 0 for decoder A. Together with A1a, selects which of the four active-low Y0a-Y3a outputs is asserted when SELECTa is low.
3	A1a	input	Address input bit 1 for decoder A. Together with A0a, selects which of the four active-low Y0a-Y3a outputs is asserted when SELECTa is low.
4	Y0a	output	Active-low decoded output 0 of decoder A. Asserted low when A1a=0, A0a=0, and SELECTa is low; otherwise high.
5	Y1a	output	Active-low decoded output 1 of decoder A. Asserted low when A1a=0, A0a=1, and SELECTa is low; otherwise high.
6	Y2a	output	Active-low decoded output 2 of decoder A. Asserted low when A1a=1, A0a=0, and SELECTa is low; otherwise high.
7	Y3a	output	Active-low decoded output 3 of decoder A. Asserted low when A1a=1, A0a=1, and SELECTa is low; otherwise high.
8	GND	power_in	Ground reference (0 V) for the device.
9	Y3b	output	Active-low decoded output 3 of decoder B. Asserted low when A1b=1, A0b=1, and SELECTb is low; otherwise high.
10	Y2b	output	Active-low decoded output 2 of decoder B. Asserted low when A1b=1, A0b=0, and SELECTb is low; otherwise high.
11	Y1b	output	Active-low decoded output 1 of decoder B. Asserted low when A1b=0, A0b=1, and SELECTb is low; otherwise high.
12	Y0b	output	Active-low decoded output 0 of decoder B. Asserted low when A1b=0, A0b=0, and SELECTb is low; otherwise high.
13	A1b	input	Address input bit 1 for decoder B. Together with A0b, selects which of the four active-low Y0b-Y3b outputs is asserted when SELECTb is low.
14	A0b	input	Address input bit 0 for decoder B. Together with A1b, selects which of the four active-low Y0b-Y3b outputs is asserted when SELECTb is low.
15	SELECTb	input	Active-low select/enable input for decoder B. When low, outputs Y0b-Y3b follow the A0b/A1b address inputs. When high, all outputs of decoder B are forced high.
16	VCC	power_in	Positive supply voltage input. Operating range 2.0 V to 5.0 V (absolute max -0.5 V to +7.0 V).

Key specifications

Parameter	Value
Manufacturer	HGSEMI
Package	SOP-16
Category	Logic
Pins	16

Ordering variants

Same part, different packaging or reel option.

74HC139MM/TR
74HC139MN
74HC139MMT/TR

CAD (KiCad official)

Symbol: 74HC139M
Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
3D model: SOP-16 (KiCad packages3D, STEP)

Provenance

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

Datasheet: HGSEMI datasheet (10 pp, sha256 7bc94cd2ebcfa7d9, 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