D State-of-the-Art BiCMOS Design
Significantly Reduces ICCZ
D Bus Transceivers/ Registers D Independent Registers and En...
D State-of-the-Art Bi
CMOS Design
Significantly Reduces ICCZ
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 3-STATE 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)
DIR SAB CLKAB NC VCC CLKBA SBA
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 VCC 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
A7 A8 GND NC B8 B7 B6
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 mo...