SN54BCT646, SN74BCT646
OCTAL BUS TRANSCEIVERS AND REGISTERS
WITH 3 STATE OUTPUTS
SCBS037D 鈭?AUGUST 1989 鈭?REVISED MAY 2004
D
State-of-the-Art BiCMOS Design
D
D
Significantly Reduces I
CCZ
Bus Transceivers/ Registers
Independent Registers and Enables for
A and B Buses
SN54BCT646 . . . JT OR W PACKAGE
SN74BCT646 . . . DW OR NT PACKAGE
(TOP VIEW)
D
Multiplexed Real-Time and Stored Data
D
ESD Protection Exceeds JESD 22
鈭?2000-V Human-Body Model (A114-A)
鈭?200-V Machine Model (A115-A)
SN54BCT646 . . . FK PACKAGE
(TOP VIEW)
A7
A8
GND
NC
B8
CLKAB
SAB
DIR
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
OE
B1
B2
B3
B4
B5
B6
B7
B8
A1
A2
A3
NC
A4
A5
A6
DIR
SAB
CLKAB
NC
V
CC
CLKBA
SBA
4 3 2
5
6
7
8
9
10
1 28 27 26
25
24
23
22
21
20
19
11
12 13 14 15 16 17 18
OE
B1
B2
NC
B3
B4
B5
NC 鈭?No internal connection
description/ordering information
These devices consist of bus transceiver circuits, D-type flip-flops, and control circuitry arranged for multiplexed
transmission of data directly from the input bus or from the internal registers. Data on the A or B bus is clocked
into the registers on the low-to-high transition of the appropriate clock (CLKAB or CLKBA) input. Figure 1
illustrates the four fundamental bus-management functions that can be performed with the 鈥橞CT646 devices.
Output-enable (OE) and direction-control (DIR) inputs are provided to control the transceiver functions. In the
transceiver mode, data present at the high-impedance port can be stored in either register or in both.
The select-control (SAB and SBA) inputs can multiplex stored and real-time (transparent mode) data. The
direction control (DIR) determines which bus will receive data when OE is low. In the isolation mode (OE high),
A data can be stored in one register and/or B data can be stored in the other register.
ORDERING INFORMATION
TA
PDIP 鈭?NT
0 C 70擄C
0擄C to 70 C
SOIC 鈭?DW
CDIP 鈭?JT
鈭?5擄C to 125 C
鈭?5 C 125擄C
CFP 鈭?W
LCCC 鈭?FK
PACKAGE鈥?/div>
Tube
Tube
Tape and reel
Tube
Tube
Tube
ORDERABLE
PART NUMBER
SN74BCT646NT
SN74BCT646DW
SN74BCT646DWR
SNJ54BCT646JT
SNJ54BCT646W
SNJ54BCT646FK
BCT646
SNJ54BCT646JT
SNJ54BCT646W
SNJ54BCT646FK
TOP-SIDE
MARKING
SN74BCT646NT
鈥?Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are
available at www.ti.com/sc/package.
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.
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.
On products compliant to MIL PRF 38535, all parameters are tested
unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.
Copyright
錚?/div>
2004, Texas Instruments Incorporated
POST OFFICE BOX 655303
鈥?/div>
DALLAS, TEXAS 75265
B7
B6
1
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