1

PS2012B

09/22/99

ProductPinConfiguration

Inputs

OE

T/R

Outputs

L

L

L

H

H

X

High Z State

1. H = High Voltage Level, X = Don't Care, L = Low

Voltage Level, Z = High Impedance

2. 640 is inverting from input to output.

PinName

Description

OE

3-State Output Enable Inputs (Active LOW)

T/R

Transmit/Receive Input

Side A Inputs or 3-State Outputs

Side B Inputs or 3-State Outputs

GND

Ground

Power

ProductPinDescription

Fast CMOS Octal

Bidirectional Transceivers

12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012

12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012

PI74FCT245T/640T/645T

PI74FCT2245T/2640T/2645T

(25Ω

Ω

Ω

Ω

Ω Series)

FCT245, 2245, 645, 2645 are non-inverting options.

FCT640 & FCT2640 are inverting options.

Logic Block Diagram

ProductDescription

Pericom Semiconductor’s PI74FCT series of logic circuits are

produced using the Company’s advanced 0.6/0.8 micron CMOS

technology, achieving industry leading speed grades. All

PI74FCT2XXXdeviceshaveabuilt-in25Ohmseriesresistoronall

outputs to reduce noise because of reflections, thus eliminating the

need for an external terminating resistor.

ThePI74FCT245T/640T/645TandPI74FCT2245T/2640T/2645Tare

8-bit wide octal buffer bidirectional transceivers designed for

asynchronous two-way communication between data buses. The

transmit/receive (T/R) input determines the direction of data flow

throughthebidirectionaltransceiver.Transmit(activeHIGH)enables

data from A ports to B ports, and receive (active LOW) from B ports

to A ports. The output enable (OE) input, when HIGH, disables both

A and B ports by placing them in HIGH Z condition.

ProductFeatures

• PI74FCT245/640/645TandPI74FCT2245/2640T/2645Tarepin

compatible with bipolar FAST™ Series at a higher speed and

lower power consumption

• 25 Ohm series resistor on all outputs (FCT2XXX only)

• TTL input and output levels

• Low ground bounce outputs

• Extremelylowstaticpower

• Hysteresis on all inputs

• Industrial operating temperature range: –40°C to +85°C

• Packagesavailable:

– 20-pin173milwideplasticTSSOP(L)

– 20-pin 300 mil wide plastic DIP (P)

– 20-pin150milwideplasticQSOP(Q)

– 20-pin150milwideplasticTQSOP(R)

– 20-pin300milwideplasticSOIC(S)

– 20-pin 209 mil wide plastic SSOP (H)

• Device models available on request

1

2

3

4

5

6

7

8

9

10

20

19

18

17

16

15

14

13

12

11

T/R

GND

Vcc

OE

20-Pin

L,P,Q

R,S,H

A0

B0

OE

A1

B1

A2

B2

A3

B3

A4

B4

A5

B5

A6

B6

A7

B7

T/R