Philips Semiconductors

Product specification

74F579

8-bit bidirectional binary counter (3-State)

2

1992 May 04

853-0377 06639

FEATURES

DESCRIPTION

The 74F579 is a fully synchronous 8-stage Up/Down Counter with

multiplexed 3-State I/O ports for bus-oriented applications. It

features a preset capability for programmable operation, carry

look-ahead for easy cascading and a U/D input to control the

direction of counting. All state changes, except for the case of

asynchronous reset, are initiated by the rising edge of the clock.

TC output is not recommended for use as a clock or asynchronous

reset due to the possibility of decoding spikes.

PIN CONFIGURATION

20

19

18

17

16

15

14

13

12

10

11

9

8

7

6

5

4

3

2

1

CP

I/O0

I/O1

I/O2

I/O3

GND

I/O4

I/O5

I/O6

I/O7

VCC

MR

SR

CEP

CET

TC

PE

CS

OE

U/D

SF01085

ORDERING INFORMATION

TYPE

TYPICAL SUPPLY

CURRENT

(TOTAL)

74F579

115MHz

100mA

ORDERING INFORMATION

DESCRIPTION

COMMERCIAL RANGE

PKG DWG #

20-Pin Plastic DIP

N74F579N

SOT146-1

20-Pin Plastic SOL

N74F579D

SOT163-1

INPUT AND OUTPUT LOADING AND FAN-OUT TABLE

PINS

DESCRIPTION

74F(U.L.)

HIGH/LOW

LOAD VALUE

HIGH/LOW

I/O

Data Inputs

3.5/1.0

70

µA/0.6mA

Data Outputs

150/40

3.0mA/24mA

PE

Parallel Enable input (active Low)

1.0/1.0

20

µA/0.6mA

U/D

Up/Down count control input

1.0/1.0

20

µA/0.6mA

MR

Master Reset input (active Low)

1.0/1.0

20

µA/0.6mA

SR

Synchronous Reset input (active Low)

1.0/1.0

20

µA/0.6mA

CEP

Count Enable Parallel input (active Low)

1.0/1.0

20

µA/0.6mA

CET

Count Enable Trickle input (active Low)

1.0/1.0

20

µA/0.6mA

CS

Chip Select input (active Low)

1.0/1.0

20

µA/0.6mA

OE

Output Enable input (active Low)

1.0/1.0

20

µA/0.6mA

CP

Clock input (active Rising Edge)

1.0/1.0

20

µA/0.6mA

TC

Terminal Count Output (active Low)

50/33

1.0mA/20mA

NOTE: One (1.0) FAST Unit Load (U.L.) is defined as: 20

µA in the High state and 0.6mA in the Low state.