National Semiconductor MM54HC149, MM74HC149 Service Manual

MM54HC149/MM74HC149
8 Line to 8 Line Priority Encoder

MM54HC149/MM74HC149 8 Line to 8 Line Priority Encoder

January 1988

General Description

This priority encoder utilizes advanced silicon-gate CMOS
technology. It has the high noise immunity and low power
consumption typical of CMOS circuits, as well as the speeds
and output drive similar to LS-TTL.

This priority encoder accepts 8 input request lines, RI7
and outputs 8 lines, RO7
can be low at a time. The output that is low is dependent on
the highest priority request that is low. The order of priority
is RI7

highest and RI0 lowest. Also provided is and enable
input, RQE
quest output is also provided, RQP
any RIn

All inputs to this device are protected from damage due to
electrostatic discharge by diodes to V

, which when high forces all outputs high. A re-

is active.

–RO0. Only one request output

, which goes low when

and ground.

CC

–RI0,

Connection Diagram

Dual-In-Line Package

Features

Y

Propagation delay: 15 ns typical

Y

Wide power supply range: 2– 6V

Y

Low quiescent current: 80 mA max (74HC Series)

Y

Wide input noise immunity

Top View

Order Number MM54HC149 or MM74HC149

TL/F/5312– 1

Truth Table

Inputs Outputs

01234567RQE01234567RQP

XXXXXXXX H HHHHHHHH H
HHHHHHHH L HHHHHHHH H
XXXXXXXL L HHHHHHHL L
XXXXXXLH L HHHHHHLH L
XXXXXLHH L HHHHHLHH L
XXXXLHHH L HHHHLHHH L
XX X L HHHH L HHH LHHHH L
XX LHHHHH L HHLHHHHH L
X LHHHHHH L HL HHHHHH L
LHHHHHHH L LHHHHHHH L

C

1995 National Semiconductor Corporation RRD-B30M105/Printed in U. S. A.

TL/F/5312

Absolute Maximum Ratings (Notes1&2)

Operating Conditions

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.

Supply Voltage (V

CC

)

DC Input Voltage (VIN)

DC Output Voltage (V

OUT

)

Clamp Diode Current (IIK,IOK)

DC Output Current, per pin (I

OUT

)

DC VCCor GND Current, per pin (ICC)

Storage Temperature Range (T

STG

b

b

)

b

0.5 toa7.0V

1.5 to V

CC

0.5 to V

CC

g

g

b

g

65§Ctoa150§C

a

1.5V

a

0.5V

20 mA

25 mA

50 mA

Supply Voltage (V

)26V

CC

DC Input or Output Voltage 0 V

(V

IN,VOUT

)

Operating Temp. Range (TA)

MM74HC
MM54HC

Input Rise or Fall Times

e

V

2.0V(tr,tf) 1000 ns

CC

e

V

4.5V 500 ns

CC

e

V

6.0V 400 ns

CC

Power Dissipation (PD)

(Note 3) 600 mW
S.O. Package only 500 mW

Lead Temperature (T

)

L

(Soldering 10 seconds) 260§C

DC Electrical Characteristics (Note 4)

Symbol Parameter Conditions V

CC

A

e

T

25§C

Typ Guaranteed Limits

V

IH

Minimum High Level 2.0V 1.5 1.5 1.5 V
Input Voltage 4.5V 3.15 3.15 3.15 V

6.0V 4.2 4.2 4.2 V

V

IL

Maximum Low Level 2.0V 0.5 0.5 0.5 V
Input Voltage** 4.5V 1.35 1.35 1.35 V

6.0V 1.8 1.8 1.8 V

V

OH

Minimum High Level V
Output Voltage

e

VIHor V

l

I

IN
OUT

IL

s

20 mA 2.0V 2.0 1.9 1.9 1.9 V

l

4.5V 4.5 4.4 4.4 4.4 V

6.0V 6.0 5.9 5.9 5.9 V

e

V

VIHor V

IN

I

l

OUT

I

l

OUT

V

OL

Maximum Low Level V
Output Voltage

l

I

IN
OUT

e

IL

s

4.0 mA 4.5V 4.2 3.98 3.84 3.7 V

l

s

5.2 mA 6.0V 5.7 5.48 5.34 5.2 V

l

VIHor V

IL

s

20 mA 2.0V 0 0.1 0.1 0.1 V

l

4.5V 0 0.1 0.1 0.1 V

6.0V 0 0.1 0.1 0.1 V

e

V

VIHor V

IN

I

l

OUT

I

l

OUT

I

IN

I

CC

Note 1: Absolute Maximum Ratings are those values beyond which damage to the device may occur.

Note 2: Unless otherwise specified all voltages are referenced to ground.

Note 3: Power Dissipation temperature derating Ð plastic ‘‘N’’ package:

Note 4: For a power supply of 5V

with this supply. Worst case V
I

**V

Maximum Input V
Current

Maximum Quiescent V
Supply Current I

g

and VILoccur at V

) occur for CMOS at the higher voltage and so the 6.0V values should be used.

OZ

limits are currently tested at 20% of VCC. The above VILspecification (30% of VCC) will be implemented no later than Q1, CY’89.

IL

IH

e

IN

e

IN

OUT

10% the worst case output voltages (VOH, and VOL) occur for HC at 4.5V. Thus the 4.5V values should be used when designing

IL

s

4.0 mA 4.5V 0.2 0.26 0.33 0.4 V

l

s

5.2 mA 6.0V 0.2 0.26 0.33 0.4 V

l

VCCor GND 6.0V

VCCor GND 6.0V 8.0 80 160 mA

e

0 mA

b

12 mW/§C from 65§Cto85§C; ceramic ‘‘J’’ package:b12 mW/§C from 100§Cto125§C.

e

5.5V and 4.5V respectively. (The VIHvalue at 5.5V is 3.85V.) The worst case leakage current (IIN,ICC, and

CC

g

0.1

74HC 54HC

eb

T

40 to 85§CT

A

g

1.0

Min Max Units

V

§

§

Units

b
b

40
55

eb

A

55 to 125§C

g

CC

a

85

a

125

1.0 mA

C
C

AC Electrical Characteristics V

CC

5V, T

e

A

25§C, C

e

L

15 pF, t

e

t

r

f

e

6 ns (Note 6)

e

Symbol Parameter Conditions Typ Guaranteed Limit Units

t

PHL,tPLH

Maximum Propagation Delay, Any Input
To Any Output 20 33 ns

2