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Contents

Pinout
Key specifications
Electrical characteristics
CAD (KiCad official)
Provenance

README

markdown

74HC138BQ

Nexperia · Logic ICs · DHVQFN-16-EP(2.5x3.5)

74HC138BQ from Nexperia, in a DHVQFN-16-EP(2.5x3.5). Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	A0	input	Address input A0 (binary weight 0) of the 3-to-8 decoder; the input voltage range is 0 V to VCC and clamp diodes are included.
2	A1	input	Address input A1 (binary weight 1) of the 3-to-8 decoder; the input voltage range is 0 V to VCC and clamp diodes are included.
3	A2	input	Address input A2 (binary weight 2) of the 3-to-8 decoder; the input voltage range is 0 V to VCC and clamp diodes are included.
4	E1	input	Enable input E1, active LOW; all outputs are HIGH unless E1 and E2 are LOW and E3 is HIGH.
5	E2	input	Enable input E2, active LOW; all outputs are HIGH unless E1 and E2 are LOW and E3 is HIGH.
6	E3	input	Enable input E3, active HIGH; all outputs are HIGH unless E1 and E2 are LOW and E3 is HIGH.
7	Y7	output	Active LOW mutually exclusive decoder output Y7; the output voltage range is 0 V to VCC.
8	GND	power_in	Ground pin at 0 V; all voltages are referenced to this pin.
9	Y6	output	Active LOW mutually exclusive decoder output Y6; the output voltage range is 0 V to VCC.
10	Y5	output	Active LOW mutually exclusive decoder output Y5; the output voltage range is 0 V to VCC.
11	Y4	output	Active LOW mutually exclusive decoder output Y4; the output voltage range is 0 V to VCC.
12	Y3	output	Active LOW mutually exclusive decoder output Y3; the output voltage range is 0 V to VCC.
13	Y2	output	Active LOW mutually exclusive decoder output Y2; the output voltage range is 0 V to VCC.
14	Y1	output	Active LOW mutually exclusive decoder output Y1; the output voltage range is 0 V to VCC.
15	Y0	output	Active LOW mutually exclusive decoder output Y0; the output voltage range is 0 V to VCC.
16	VCC	power_in	Supply voltage; 2.0 V to 6.0 V for 74HC138 and 4.5 V to 5.5 V for 74HCT138 per the recommended operating conditions, with a maximum absolute rating of +7 V.
17	EP	passive	Exposed pad (from the footprint; not named in the datasheet pin table).

Key specifications

Parameter	Value
Manufacturer	Nexperia
Package	DHVQFN-16-EP(2.5x3.5)
Category	Logic ICs
Pins	17

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter	Symbol	Min	Typ	Max	Unit	Conditions	Page
supply voltage	VCC	-0.5		7	V		4
input clamping current	IIK	-20		20	mA	VI < -0.5 V or VI > VCC + 0.5 V	4
output clamping current	IOK	-20		20	mA	VO < -0.5 V or VO > VCC + 0.5 V	4
output current	IO	-25		25	mA	VO = -0.5 V to (VCC + 0.5 V)	4
quiescent supply current	ICC			50	mA		4
ground current	IGND	-50			mA		4
storage temperature	Tstg	-65		150	°C		4
total power dissipation	Ptot			500	mW		4
supply voltage	VCC	2	5	6	V		5
ambient temperature	Tamb	-40	25	125	°C		5
input transition rise and fall rate	Δt/ΔV			625	ns/V	VCC = 2.0 V	5
input transition rise and fall rate	Δt/ΔV		1.67	139	ns/V	VCC = 4.5 V	5
input transition rise and fall rate	Δt/ΔV			83	ns/V	VCC = 6.0 V	5
HIGH-level input voltage	VIH	1.5	1.2		V	VCC = 2.0 V	5
HIGH-level input voltage	VIH	3.15	2.4		V	VCC = 4.5 V	5
HIGH-level input voltage	VIH	4.2	3.2		V	VCC = 6.0 V	5
LOW-level input voltage	VIL		0.8	0.5	V	VCC = 2.0 V	5
LOW-level input voltage	VIL		2.1	1.35	V	VCC = 4.5 V	5
LOW-level input voltage	VIL		2.8	1.8	V	VCC = 6.0 V	5
HIGH-level output voltage	VOH	1.9	2		V	IO = -20 μA; VCC = 2.0 V	5
HIGH-level output voltage	VOH	4.4	4.5		V	IO = -20 μA; VCC = 4.5 V	5
HIGH-level output voltage	VOH	5.9	6		V	IO = -20 μA; VCC = 6.0 V	5
HIGH-level output voltage	VOH	3.98	4.32		V	IO = -4.0 mA; VCC = 4.5 V	5
HIGH-level output voltage	VOH	5.48	5.81		V	IO = -5.2 mA; VCC = 6.0 V	5
LOW-level output voltage	VOL		0	0.1	V	IO = 20 μA; VCC = 2.0 V	5
LOW-level output voltage	VOL		0.15	0.26	V	IO = 4.0 mA; VCC = 4.5 V	5
LOW-level output voltage	VOL		0.16	0.26	V	IO = 5.2 mA; VCC = 6.0 V	5
input leakage current	II	-0.1		0.1	μA	VI = VCC or GND; VCC = 6.0 V	5
supply current	ICC			8	μA	VI = VCC or GND; IO = 0 A; VCC = 6.0 V	5
input capacitance	CI		3.5		pF		5
propagation delay An to Yn	tpd		41	150	ns	An to Yn; see Fig. 4; VCC = 2.0 V	7
propagation delay An to Yn	tpd		15	30	ns	An to Yn; see Fig. 4; VCC = 4.5 V	7
propagation delay An to Yn	tpd		12		ns	An to Yn; see Fig. 4; VCC = 5 V; CL = 15 pF	7
propagation delay An to Yn	tpd		12	26	ns	An to Yn; see Fig. 4; VCC = 6.0 V	7
propagation delay E3 to Yn	tpd		47	150	ns	E3 to Yn; see Fig. 4; VCC = 2.0 V	7
propagation delay E3 to Yn	tpd		17	20	ns	E3 to Yn; see Fig. 4; VCC = 4.5 V	7
propagation delay E3 to Yn	tpd		14		ns	E3 to Yn; see Fig. 4; VCC = 5 V; CL = 15 pF	7
propagation delay E3 to Yn	tpd		14	26	ns	E3 to Yn; see Fig. 4; VCC = 6.0 V	7
propagation delay En to Yn	tpd		47	150	ns	En to Yn; see Fig. 5; VCC = 2.0 V	7
propagation delay En to Yn	tpd		17	20	ns	En to Yn; see Fig. 5; VCC = 4.5 V	7
propagation delay En to Yn	tpd		14		ns	En to Yn; see Fig. 5; VCC = 5 V; CL = 15 pF	7
propagation delay En to Yn	tpd		14	26	ns	En to Yn; see Fig. 5; VCC = 6.0 V	7
propagation delay Yn	tpd		19	75	ns	Yn; see Fig. 4 and Fig. 5; VCC = 2.0 V	7
propagation delay Yn	tpd		7	15	ns	Yn; see Fig. 4 and Fig. 5; VCC = 4.5 V	7
transition time	tt		6	13	ns	Yn; see Fig. 4 and Fig. 5; VCC = 6.0 V	7
power dissipation capacitance	CPD		67		pF	CL = 50 pF; f = 1 MHz; VI = GND to VCC	7
thermal derating of total power dissipation	Ptot		11.2		mW/K	SOT763-1 (DHVQFN16); derates linearly above 106 °C	4

CAD (KiCad official)

Symbol: 74HC138BQ
Footprint: Package_DFN_QFN:DHVQFN-16-1EP_2.5x3.5mm_P0.5mm_EP1x2mm
3D model: DHVQFN-16-EP(2.5x3.5), generated from the KiCad footprint (body from the F.Fab outline, terminals on the pads, 0.9 mm nominal VQFN height). Neither the vendor nor KiCad ships a 3D model for this package, so the dimensions are nominal, not the manufacturer's CAD (STEP)
3D model files: 74hc138bq-etched.step / 74hc138bq-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); 74hc138bq.step / 74hc138bq.glb are the bare package body.

Provenance

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

Datasheet: Nexperia datasheet (15 pp, sha256 645120bc441507e9, retrieved 2026-10-17, tier: manufacturer)
Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-5-5 (text), consensus claude-sonnet-5-5 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF