MOTOROLA MC74ACT139MEL, MC74ACT139DTR2, MC74ACT139DTEL, MC74ACT139DR2, MC74ACT139DT Datasheet

MC74AC139

MC74ACT139

Dual 1 of 4 Decoder/Demultiplexer	DUAL 1-OF-4

DECODER/DEMULTIPLEXER

The MC74AC139/74ACT139 is a high-speed, dual 1-of-4 decoder/demultiplexer. The device has two independent decoders, each accepting two inputs and providing four mutually-exclusive active-LOW outputs. Each decoder has an active-LOW Enable input which can be used as a data input for a 4-output demultiplexer. Each half of the MC74AC139/74ACT139 can be used as a function generator providing four minterms of two variables.

• Multifunction Capability
• Two Completely Independent 1-of-4 Decoders
• Active LOW Mutually Exclusive Outputs
• Outputs Source/Sink 24 mA
• ′ACT139 Has TTL Compatible Inputs								N SUFFIX
VCC	Eb	A0b	A1b	O0b	O1b	O2b	O3b	CASE 648-08
								PLASTIC
16	15	14	13	12	11	10	9

PIN NAMES

D SUFFIX

A

0, A1

Address Inputs

CASE 751B-05

1

2

3

4

5

6

7

8

E

Enable Inputs

PLASTIC

Ea

A0a

A1a

O0a

O1a

O2a

O3a

GND

O0±O3

Outputs

TRUTH TABLE

LOGIC SYMBOL

Inputs

Outputs

E

A0

A1

O0

O1

O2

O3

E A0 A1

H

X

X

H

H

H

H

DECODER a

L

L

L

L

H

H

H

L

H

L

H

L

H

H

O0 O1 O2 O3

L

L

H

H

H

L

H

L

H

H

H

H

H

L

H = HIGH Voltage Level

L = LOW Voltage Level

X = Immaterial

E A0 A1 DECODER b O0 O1 O2 O3

FACT DATA

5-1

MC74AC139 MC74ACT139

LOGIC DIAGRAM

Ea

A0a

A1a

Eb

A0b

A1b

00a

01a

02a

03a

00b

01b

02b

03b

Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.

FUNCTIONAL DESCRIPTION

The MC74AC139/74ACT139 is a high-speed dual 1-of-4 decoder/demultiplexer. The device has two independent decoders, each of which accepts two binary weighted inputs (A0±A1) and provides four mutually exclusive active-LOW outputs (O0±O3). Each decoder has an active-LOW enable

(E). When E is HIGH all outputs are forced HIGH. The enable can be used as the data input for a 4-output demultiplexer application. Each half of the MC74AC139/74ACT139 generates all four minterms of two variables. These four minterms are useful in some applications, replacing multiple gate functions as shown in Figure a, and thereby reducing the number of packages required in a logic network.

E		E
A0	O0	A0		O0
A1		A1
E		E
A0	O	A0		O
	1			1
A1		A1
E		E
A0	O	A	0	O
	2			2
A1		A1
E		E
A0	O3	A0		O3
A1		A1

Figure a: Gate Functions (each half)

MAXIMUM RATINGS*

Symbol	Parameter	Value	Unit
VCC	DC Supply Voltage (Referenced to GND)	±0.5 to +7.0	V
Vin	DC Input Voltage (Referenced to GND)	±0.5 to VCC +0.5	V
Vout	DC Output Voltage (Referenced to GND)	±0.5 to VCC +0.5	V
Iin	DC Input Current, per Pin	±20	mA
Iout	DC Output Sink/Source Current, per Pin	±50	mA
ICC	DC VCC or GND Current per Output Pin	±50	mA
Tstg	Storage Temperature	±65 to +150	°C

*Maximum Ratings are those values beyond which damage to the device may occur. Functional operation should be restricted to the Recommended Operating Conditions.

FACT DATA

5-2