Philips N74F621N, N74F621D Datasheet

INTEGRATED CIRCUITS

74F621

Octal bus transceiver, non-inverting (open collector)

Product specification 1996 Jan 05 IC15 Data Handbook

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Philips Semiconductors Product specification

74F621Octal bus transceiver, non-inverting (open collector)

FEA TURES

•High-impedance NPN base inputs for reduced loading

(20µA in High and Low states)

•Octal bidirectional bus interface

•Open collector outputs sink 64mA

•Non-inverting

DESCRIPTION

The 74F621 is an octal transceiver featuring non-inverting open collector bus-compatible outputs in both send and receive directions. The outputs are capable of sinking 64mA, providing very good capacitive drive characteristics.

This octal bus transceiver is designed for asynchronous two-way communication between data buses. The control function implementation allows for maximum flexibility in timing.

The device allows 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 disable the device so that the buses are effectively isolated.

The dual-enable configuration gives the 74F621 the capability to store data by the simultaneous enabling of OEBA 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.

and OEAB). The Enable inputs can be used to

and OEAB. Each

PIN CONFIGURATION

OEAB

10 11

GND

TYPICAL

TYPE

PROPAGATION

DELAY

74F621 8.0ns 105mA

OEBA B0

SF01135

TYPICAL SUPPLY CURRENT

(TOTAL)

ORDERING INFORMATION

COMMERCIAL RANGE

DESCRIPTION

VCC = 5V ±10%,

= 0°C to +70°C

amb

20-pin plastic DIP N74F621N SOT146-1

20-pin plastic SOL N74F621D SOT163-1

PKG

DWG #

INPUT AND OUTPUT LOADING AND FAN-OUT TABLE

PINS DESCRIPTION

74F(U.L.)

HIGH/LOW

A0 - A7, B0 - B7 Data inputs 1.0/0.033 20µA/20µA OEBA, OEAB Output Enable inputs 1.0/0.033 20µA/20µA A0 - A7 Data outputs OC/40 OC/24mA B0 - B7 Data outputs OC/106.7 OC/64mA

NOTE: One (1.0) FAST unit load is defined as: 20µA in the High state and 0.6mA in the Low state. OC = Open Collector.

LOAD VALUE

HIGH/LOW

1996 Jan 05 853–0380 16185

Philips Semiconductors Product specification

OPERATING MODES

74F621Octal bus transceiver, non-inverting (open collector)

LOGIC SYMBOL

A0 A1

OEAB

OEBA

B0 B1 B2 B3

18 17 16 15 14 13 12 11

VCC= Pin 20 GND = Pin 10

LOGIC DIAGRAM

OEBA

OEAB

456

A2 A3

A4 A5 A67A7

B4 B5 B6 B7

SF01126

LOGIC SYMBOL (IEEE/IEC)

19 1

EN1 EN2

SF01137

FUNCTION TABLE

INPUTS

OEBA OEAB

L L B data to A bus H H A data to B bus H L OFF

B data to A bus A data to B bus

H = High voltage level L = Low voltage level X = Don’t care OFF= High if pull-up resistor is connected to open collector output

VCC= Pin 20 GND = Pin 10

1996 Jan 05

SF01130

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