74ACT11646 Datasheet, PDF (1/11 Pages) Texas Instruments – OCTAL BUS TRANSCEIVER AND REGISTER WITH 3-STATE OUTPUTS

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• Independent Registers for A and B Buses
• Multiplexed Real-Time and Stored Data
• Flow-Through Architecture Optimizes
PCB Layout
• Center-Pin V_CC and GND Configurations
Minimize High-Speed Switching Noise
• EPICt (Enhanced-Performance Implanted
CMOS) 1-mm Process
• 500-mA Typical Latch-Up Immunity at 125°C
description
These devices consist of bus transceiver circuits,
3-state outputs, D-type flip-flops, and control
circuitry arranged for multiplexed transmission of
data directly from the data bus or from the internal
storage registers. Data on the A or B bus will be
clocked into the registers on the low-to-high
transition of the appropriate clock pin (CAB or
CBA). Figure 1 illustrates the four fundamental
bus-management functions that can be performed
with the octal bus transceivers and registers.
74ACT11646
OCTAL BUS TRANSCEIVER AND REGISTER
WITH 3ĆSTATE OUTPUTS
SCAS061A − D2957, JULY 1987 − REVISED APRIL 1993
DW PACKAGE
(TOP VIEW)
G₁
A1 2
A2 3
A3 4
A4 5
GND 6
GND 7
GND 8
GND 9
A5 10
A6 ¹¹
A7 ¹²
A8 ¹³
DIR ¹⁴
28 ^CAB
27 SAB
26 B1
25 B2
24 B3
23 B4
22 V_CC
21 V_CC
20 B5
19 B6
18 _B7
17 _B8
16 _CBA
15 _SBA
Enable (G) and direction (DIR) pins are provided to control the transceiver functions. In the transceiver mode,
data present at the high-impedance port may be stored in either register or in both. The select controls (SAB
and SBA) can multiplex stored and real-time (transparent mode) data. The circuitry used for select control will
eliminate the typical decoding glitch which occurs in a multiplexer during the transition between stored and
real-time data. The direction control determines which bus will receive data when enable G is active (low). In
the isolation mode (control G high), A data may be stored in one register and/or B data may be stored in the
other register.
When an output function is disabled, the input function is still enabled and may be used to store and transmit
data. Only one of the two buses, A or B, may be driven at a time.
The 74ACT11646 is characterized for operation from − 40°C to 85°C.
EPIC is a trademark of 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.
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Copyright  1993, Texas Instruments Incorporated
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