Philips Semiconductors

Product specification

74F620/74F623

Transceivers

74F620 Octal Bus Transceiver, Inverting (3-State)

74F623 Octal Bus Transceiver, Non-Inverting (3-State)

2

1990 Apr 6

853–0379 96249

FEATURES

(70

µA in High and Low states)

bus loading

DESCRIPTION

The 74F620 is an octal transceiver featuring inverting 3-State

bus-compatible outputs in both send and receive directions. The

outputs are capable of sinking 64mA and sourcing up to 15mA,

providing very good capacitive drive characteristics. The 74F623 is

a non-inverting version of the 74F620.

These octal bus transceivers are designed for asynchronous

two-way communication between data buses. The control function

implementation allows for maximum flexibility in timing.

These devices allow data transmission from the A bus to the B bus

or from the B bus to the A bus depending upon the logic levels at the

Enable inputs (OEBA and OEAB). The Enable inputs can be used to

disable the device so that the buses are effectively isolated.

The dual-enable configuration gives the 74F620 and 74F623 the

capability to store data by the simultaneous enabling of OEBA and

OEAB. Each output reinforces its input in this transceiver

configuration. Thus, when both control inputs are enabled and all

other data sources to the two sets of the bus lines are at high

impedance, both sets of bus lines (16 in all) will remain in their last

states.

TYPE

TYPICAL

PROPAGATION

DELAY

TYPICAL SUPPLY CURRENT

(TOTAL)

74F620

3.5ns

80mA

74F623

4.5ns

105mA

ORDERING INFORMATION

DESCRIPTION

COMMERCIAL RANGE

PKG DWG #

20-pin plastic DIP

N74F620N, N74623N

SOT146-1

20-pin plastic SOL

N74F620D, N74623D

SOT163-1

INPUT AND OUTPUT LOADING AND FAN-OUT TABLE

PINS

DESCRIPTION

74F(U.L.)

HIGH/LOW

LOAD VALUE

HIGH/LOW

A0 - A7, B0 - B7

Data inputs

3.5/1.16

70

µA/70µA

OEBA, OEAB

Output Enable inputs

1.0/0.033

20

µA/20µA

A0 - A7

Data outputs

150/40

3mA/24mA

B0 - B7

Data outputs

750/106.7

15mA/64mA

NOTE: One (1.0) FAST unit load is defined as: 20

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

PIN CONFIGURATION – 74F620

20

19

18

17

16

15

14

13

12

10

11

9

8

7

6

5

4

3

2

1

VCC

B1

B2

B3

B4

B5

B6

B7

OEAB

A1

A2

A3

A4

A5

A6

A7

GND

OEBA

A0

B0

SF01124

PIN CONFIGURATION – 74F623

20

19

18

17

16

15

14

13

12

10

11

9

8

7

6

5

4

3

2

1

VCC

B1

B2

B3

B4

B5

B6

B7

OEAB

A1

A2

A3

A4

A5

A6

A7

GND

OEBA

A0

B0

SF01124