SN54BCT646_08 Datasheet, PDF (1/18 Pages) Texas Instruments – OCTAL BUS TRANSCEIVERS AND REGISTERS WITH 3-STATE OUTPUTS

D State-of-the-Art BiCMOS Design
Significantly Reduces I_CCZ
D Bus Transceivers/ Registers
D Independent Registers and Enables for
A and B Buses
SN54BCT646 . . . JT OR W PACKAGE
SN74BCT646 . . . DW OR NT PACKAGE
(TOP VIEW)
SN54BCT646, SN74BCT646
OCTAL BUS TRANSCEIVERS AND REGISTERS
WITH 3ĆSTATE OUTPUTS
SCBS037D − AUGUST 1989 − REVISED MAY 2004
D Multiplexed Real-Time and Stored Data
D ESD Protection Exceeds JESD 22
− 2000-V Human-Body Model (A114-A)
− 200-V Machine Model (A115-A)
SN54BCT646 . . . FK PACKAGE
(TOP VIEW)
CLKAB 1
SAB 2
DIR 3
A1 4
A2 5
A3 6
A4 7
A5 8
A6 9
A7 10
A8 11
GND 12
24 V_CC
23 CLKBA
22 SBA
21 OE
20 B1
19 B2
18 B3
17 B4
16 B5
15 B6
14 B7
13 B8
4 3 2 1 28 27 26
A1 5
25 OE
A2 6
24 B1
A3 7
23 B2
NC 8
22 NC
A4 9
21 B3
A5 10
20 B4
A6
1112
13
14
15
16
17
19
18
B5
description/ordering information
NC − No internal connection
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 ’BCT646 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
PACKAGE†
ORDERABLE
PART NUMBER
TOP-SIDE
MARKING
PDIP − NT
Tube
SN74BCT646NT
SN74BCT646NT
0°C to 70°C
SOIC − DW
Tube
Tape and reel
SN74BCT646DW
SN74BCT646DWR
BCT646
CDIP − JT
Tube
SNJ54BCT646JT
SNJ54BCT646JT
−55°C to 125°C CFP − W
Tube
SNJ54BCT646W
SNJ54BCT646W
LCCC − FK
Tube
SNJ54BCT646FK
SNJ54BCT646FK
† _{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.
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
Copyright  2004, Texas Instruments Incorporated
On products compliant to MILĆPRFĆ38535, all parameters are tested
unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.
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