SN54BCT652, SN74BCT652
OCTAL BUS TRANSCEIVERS AND REGISTERS
WITH 3-STATE OUTPUTS
SCBS038A – AUGUST 1989 – REVISED NOVEMBER 1993
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State-of-the-Art BiCMOS Design
Significantly Reduces I
CCZ
ESD Protection Exceeds 2000 V Per
MIL-STD-883C, Method 3015; Exceeds
200 V Using Machine Model (C = 200 pF,
R = 0)
Independent Registers and Enables for
A and B Buses
Multiplexed Real-Time and Stored Data
Power-Up High-Impedance Mode
Package Options Include Plastic
Small-Outline (DW) Packages, Ceramic
Chip Carriers (FK) and Flatpacks (W), and
Standard Plastic and Ceramic 300-mil DIPs
(JT, NT)
SN54BCT652 . . . JT OR W PACKAGE
SN74BCT652 . . . DW OR NT PACKAGE
(TOP VIEW)
CLKAB
SAB
OEAB
A1
A2
A3
A4
A5
A6
A7
A8
GND
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
V
CC
CLKBA
SBA
OEBA
B1
B2
B3
B4
B5
B6
B7
B8
description
These devices consist of bus transceiver circuits,
D-type flip-flops, and control circuitry arranged for
multiplexed transmission of data directly from the
data bus or from the internal storage registers.
Output-enable (OEAB and OEBA) inputs are
provided to control the transceiver functions.
Select-control (SAB and SBA) inputs are provided
to select whether real-time or stored data is
transferred. The circuitry used for select control
eliminates the typical decoding glitch that occurs
in a multiplexer during the transition between
stored and real-time data. A low input selects
real-time data, and a high input selects stored
data. Figure 1 illustrates the four fundamental
bus-management functions that can be performed
with the
′BCT652.
SN54BCT652 . . . FK PACKAGE
(TOP VIEW)
OEAB
SAB
CLKAB
NC
V
CC
CLKBA
SBA
4
3 2 1 28 27 26
A1
A2
A3
NC
A4
A5
A6
5
6
7
8
9
10
25
24
23
22
21
20
19
11
12 13 14 15 16 17 18
OEBA
B1
B2
NC
B3
B4
B5
A7
A8
GND
NC
B8
B7
NC – No internal connection
Data on the A or B data bus, or both, can be stored in the internal D-type flip-flops by low-to-high transitions at
the appropriate clock (CLKAB or CLKBA) inputs regardless of the select- or enable-control pins. When SAB and
SBA are in the real-time transfer mode, it is possible to store data without using the internal D-type flip-flops by
simultaneously enabling OEAB and OEBA. In this configuration each output reinforces its input. Therefore,
when all other data sources to the two sets of bus lines are at high impedance, each set of bus lines remain at
its last state.
The SN54BCT652 is characterized for operation over the full military temperature range of – 55°C to 125°C. The
SN74BCT652 is characterized for operation from 0°C to 70°C.
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.
Copyright
©
1993, Texas Instruments Incorporated
POST OFFICE BOX 655303
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DALLAS, TEXAS 75265
B6
2–1
TI [ TEXAS INSTRUMENTS ]
