1

PS2022A 03/11/96

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PI74FCT646/648/651/652T

(25

Ω

Ω

Ω

Ω

Ω Series) P174FCT2646T/2652T

OCTAL REGISTERED TRANSCEIVERS

Product Description:

Pericom Semiconductor’s PI74FCT series of logic circuits are

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

technology, achieving industry leading speed grades. All

PI74FCT2XXX devices have a built-in 25-ohm series resistor on

all outputs to reduce noise because of reflections, thus eliminating

the need for an external terminating resistor.

The PI74FCT646T/648T/651T/652T and PI74FCT2646T/2652T

are designed with a bus transceiver with 3-state D-type flip-flops

and control circuitry arranged for multiplexed transmission of data

directly from the data bus or from the internal storage registers. The

PI74FCT651/652T/2652T utilize GAB and GBA signals to control

the transceiver functions. The PI74FCT646/2646T/648T utilize

the enable control (G) and direction pins (DIR) to control the

transceiver functions. SAB and SBA control pins are used to select

either real-time or stored data transfer. The circuitry used for select

control will eliminate the typical decoding glitch that occurs in a

multiplexer during the transition between real-time and stored data.

A low input level selects real-time data and a high selects stored

data.

The PI74FCT646T is a non-inverting option of the PI74FCT648T.

The PI74FCT652T is a non-inverting option of the PI74FCT651T.

Fast CMOS Octal Registered Transceivers

Logic Block Diagram

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PI74FCT646T/648T/651T/652T

(25

Ω

Ω

Ω

Ω

Ω Series PI74FCT2646T/2652T

Product Features:

• PI74FCT646T/648T/651T/652T/2646T/2652Tispincompatible

with bipolar FAST™ Series at a higher speed and lower power

consumption

•25

Ω series resistor on all outputs (FCT2XXX only)

• TTL input and output levels

• Low ground bounce outputs

• Extremely low static power

• Hysteresis on all inputs

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

• Packages available:

– 24-pin 300 mil wide plastic DIP (P)

– 24-pin 150 mil wide plastic QSOP (Q)

– 24-pin 150 mil wide plastic TQSOP (R)

– 24-pin 300 mil wide plastic SOIC (S)

• Device models available upon request

0D

CPAB

CPBA

SBA

DIR

G

SAB

0D

A REG

B REG

1 OR 8 CHANNELS

TO 7 OTHER CHANNELS

GBA

GAB

PI74FCT651/652 ONLY

PI74FCT651/652 ONLY

646/652

ONLY

646/652

ONLY

PI74FCT646/648

ONLY