CD74FCT2952A

BiCMOS OCTAL BUS TRANSCEIVER AND REGISTER

WITH 3-STATE OUTPUTS

SCBS720 – JULY 2000

1

POST OFFICE BOX 655303

Power

and Circuit Design

description

The CD74FCT2952A is an octal transceiver and register, consisting of two 8-bit, back-to-back registers that

store data flowing in both directions between two bidirectional buses. It uses a small-geometry BiCMOS

technology. Data on the A or B bus is stored in the registers on the low-to-high transition of the clock (CLKAB

or CLKBA) input if the clock-enable (CLKENAB or CLKENBA) input is low. Taking the output-enable (OEAB or

OEBA) input low accesses the data on either port.

This device contains two 8-bit, back-to-back registers that store data flowing in both directions between two

bidirectional buses. Each register has separate clock, clock enable, and 3-state output enable signals

associated with it.

The output stage is a combination of bipolar and CMOS transistors that limits the output high level to two diode

simultaneous output switching. The output configuration also enhances switching speed and is capable of

sinking 64 mA.

resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.

The CD74FCT2952A is characterized for operation from 0

°C to 70°C.

FUNCTION TABLE†

INPUTS

OUTPUT

CLKENAB

CLKAB

OEAB

A

B

H

X

L

X

B0‡

X

H or L

L

X

B0‡

L

↑

LL

L

L

↑

LH

H

X

X

H

X

Z

† A-to-B data flow is shown; B-to-A data flow is similar,

but uses CLKENBA, CLKBA, and OEBA.

‡ Level of B before the indicated steady-state input

conditions were established

Copyright

© 2000, Texas Instruments Incorporated

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

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24

23

22

21

20

19

18

17

16

15

14

13

B8

B7

B6

B5

B4

B3

B2

B1

OEAB

CLKAB

CLKENAB

GND

A8

A7

A6

A5

A4

A3

A2

A1

OEBA

CLKBA

CLKENBA

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