Philips Semiconductors

Product specification

74F777

Triple bidirectional latched bus transceiver (3–State +

Open Collector)

2

May 19, 1992

853–1645 06772

FEATURES

swing

DESCRIPTION

The 74F777 is a triple bidirectional latched bus transceiver and is

intended to provide the electrical interface to a high performance

wired–OR bus. This bus has a loaded characteristics impedance

range of 20 to 50 ohms and is terminated on each end with a 30 to

40 ohm resistor.

The 74F777 is a triple bidirectional transceiver with Open Collector

B and 3–State A port output drivers. A latch function is provided for

the A port signals. The B port output driver is designed to sink

100mA from 2 volts to minimize crosstalk and ringing on the bus.

prevent the A port output High level from exceeding future high

TYPE

TYPICAL

PROPAGATION DELAY

TYPICAL SUPPLY CUR-

RENT( TOTAL)

74F777

7.0ns

45mA

ORDERING INFORMATION

ORDER CODE

DESCRIPTION

COMMERCIAL RANGE

INDUSTRIAL RANGE

PKG DWG #

20–pin plastic DIP (300 mil)

N74F777N

I74F777N

SOT146-1

20–pin PLCC

N74F777A

I74F777A

SOT380-1

INPUT AND OUTPUT LOADING AND FAN OUT TABLE

PINS

DESCRIPTION

74F (U.L.)

HIGH/LOW

LOAD VALUE

HIGH/LOW

A0 – A2

PNP latched inputs

3.5/0.117

70

µA/70µA

B0 – B2

Data inputs with threshold circuitry

5.0/0.167

100

µA/100µA

OEA0 – OEA2

A output enable inputs (active–High)

1.0/0.033

20

µA/20µA

OEB0 – OEB2

B output enable inputs (active–Low)

1.0/0.033

20

µA/20µA

LE0 – LE2

Latch enable inputs (active–Low)

1.0/0.033

20

µA/20µA

A0 – A2

3–State outputs

150/40

3mA/24mA

B0 – B2

Open Collector outputs

OC/166.7

OC/100mA

Note to input and output loading and fan out table

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

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

OC = Open Collector.