8-Bit Transceiver

CY74FCT2245T

SCCS037 - July 1994 - Revised March 2000

Data sheet acquired from Cypress Semiconductor Corporation.

Data sheet modified to remove devices not offered.

Copyright

Features

• Function and pinout compatible with FCT and F logic

• 25

Ω output series resistors to reduce transmission line

reflection noise

• FCT-C speed at 4.1 ns max.

FCT-A speed at 4.6 ns max.

• Edge-rate control circuitry for significantly improved

noise characteristics

• Power-off disable feature

• Fully compatible with TTL input and output logic levels

• ESD > 2000V

• Sink current

12 mA

Source current

15 mA

• Extended commercial temp. range of –40˚C to +85˚C

• Three-state outputs

Functional Description

The FCT2245T contains eight non-inverting, bidirectional buffers

with three-state outputs intended for bus oriented applications.

On-chip termination resistors have been added to the outputs to

reduce system noise caused by reflections. For this reason, the

FCT2245T can be used in an existing design to replace the

FCT245T. The FCT2245T current sinking capability is 12 mA at the

A and B ports.

The Transmit/Receive (T/R) input determines the direction of data

flow through the bidirectional transceiver. Transmit (Active HIGH)

enables data from A ports to B ports; receive (Active LOW) enables

data from B ports to A ports. The output enable (OE) input, when

HIGH, disables both the A and B ports by putting them in a High Z

condition.

The outputs are designed with a power-off disable feature to

allow for live insertion of boards.

Inputs

Output

OE

T/R

L

L

Bus B Data to Bus A

L

H

Bus A Data to Bus B

H

X

High Z State

Note:

1.

H = HIGH Voltage Level. L = LOW Voltage Level. X = Don’t Care.

Logic Block Diagram

Pin Configurations

FCT2245T–1

OE

T/R

1

2

3

4

5

6

7

8

9

10

11

12

16

17

18

19

20

13

14

FCT2245T–3

15

Top View

OE

T/R

GND

DIP/SOIC/QSOP