ST M54HC42, M74HC42 User Manual

M54HC42

.HIGH SPEED

.tPD = 13 ns (TYP.) AT VCC = 5 V LOW POWER DISSIPATION

.ICC = 4 μA (MAX.) AT TA = 25 °C HIGH NOISE IMMUNITY

.VNIH = VNIL = 28 % VCC (MIN.) OUTPUT DRIVE CAPABILITY

.10 LSTTL LOADS

SYMMETRICAL OUTPUT IMPEDANCE

.|IOH| = IOL = 4 mA (MIN.)

BALANCED PROPAGATION DELAYS

.tPLH = tPHL

WIDE OPERATING VOLTAGE RANGE

.VCC (OPR) = 2 V TO 6 V

PIN AND FUNCTION COMPATIBLE WITH 54/74LS42

DESCRIPTION

The M54/74HC42 is a high speed CMOS BCD-TO- DECIMAL DECODER fabricated in silicon gate C2MOS technology.

It has the same high speed performance of LSTTL combined with true CMOS low power consumption. A BCD code applied to the four inputs A-D selects one of ten decimal outputs Y0-Y9, which goes low to fifteen gives a high level at all outputs. This device also can be used as a 3-to-8 LINE DECODER, when the D input is assigned as a disable input. This device is useful for code conversion, address decoding, memory selection, demultiplexing, or readout decoding.

All inputs are equipped with protection circuits against static discharge and transient excess voltage.

INPUT AND OUTPUT EQUIVALENT CIRCUIT

M54HC42

M74HC42

BCD TO DECIMAL DECODER

B1R	F1R
(Plastic Package)	(Ceramic Package)

M1R	C1R
(Micro Package)	(Chip Carrier)
ORDER CODES :
M54HC42F1R	M74HC42M1R
M74HC42B1R	M74HC42C1R

PIN CONNECTIONS (top view)

NC =

No Internal

Connection

December 1992

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M54/M74HC42

PIN DESCRIPTION		IEC LOGIC SYMBOL
PIN No	SYMBOL	NAME AND FUNCTION
15, 14, 13,	A, B, C, D	Data Inputs
12
1, 2, 3, 4,	Y0 to Y9	Multiplexer Outputs
5, 6, 7, 9,
10, 11
8	GND	Ground (0V)
16	VCC	Positive Supply Voltage

LOGIC DIAGRAM

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M54/M74HC42

FUNCTIONAL TABLE

CODE No.

BCD INPUTS

DECIMAL OUTPUTS

D

C

B

A

Y0

Y1

Y2

Y3

Y4

Y5

Y6

Y7

Y8

Y9

0

L

L

L

L

L

H

H

H

H

H

H

H

H

H

1

L

L

L

H

H

L

H

H

H

H

H

H

H

H

2

L

L

H

L

H

H

L

H

H

H

H

H

H

H

3

L

L

H

H

H

H

H

L

H

H

H

H

H

H

4

L

H

L

L

H

H

H

H

L

H

H

H

H

H

5

L

H

L

H

H

H

H

H

H

L

H

H

H

H

6

L

H

H

L

H

H

H

H

H

H

L

H

H

H

7

L

H

H

H

H

H

H

H

H

H

H

L

H

H

8

H

L

L

L

H

H

H

H

H

H

H

H

L

H

9

H

L

L

H

H

H

H

H

H

H

H

H

H

L

10

H

L

H

L

H

H

H

H

H

H

H

H

H

H

11

H

L

H

H

H

H

H

H

H

H

H

H

H

H

12

H

H

L

L

H

H

H

H

H

H

H

H

H

H

13

H

H

L

H

H

H

H

H

H

H

H

H

H

H

14

H

H

H

L

H

H

H

H

H

H

H

H

H

H

15

H

H

H

H

H

H

H

H

H

H

H

H

H

H

ABSOLUTE MAXIMUM RATINGS

Symbol	Parameter	Value	Unit
VCC	Supply Voltage	-0.5 to +7	V
VI	DC Input Voltage	-0.5 to VCC + 0.5	V
VO	DC Output Voltage	-0.5 to VCC + 0.5	V
IIK	DC Input Diode Current	± 20	mA
IOK	DC Output Diode Current	± 20	mA
IO	DC Output Source Sink Current Per Output Pin	± 25	mA
ICC or IGND	DC VCC or Ground Current	± 50	mA
PD	Power Dissipation	500 (*)	mW
Tstg	Storage Temperature	-65 to +150	oC
TL	Lead Temperature (10 sec)	300	oC

Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition isnotimplied.

(*) 500 mW: 65 oC derate to 300 mW by 10mW/oC: 65 oC to 85 oC

RECOMMENDED OPERATING CONDITIONS

Symbol	Parameter		Value	Unit
VCC	Supply Voltage		2 to 6	V
VI	Input Voltage		0 to VCC	V
VO	Output Voltage		0 to VCC	V
Top	Operating Temperature: M54HC Series		-55 to +125	oC
	M74HC Series		-40 to +85	oC
tr, tf	Input Rise and Fall Time	VCC = 2 V	0 to 1000	ns
		VCC = 4.5 V	0 to 500
		VCC = 6 V	0 to 400

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