SN54ABT843 Datasheet, PDF (1/17 Pages) Texas Instruments – 9-BIT BUS-INTERFACE D-TYPE LATCHES WITH 3-STATE OUTPUTS

SN54ABT843, SN74ABT843
9-BIT BUS-INTERFACE D-TYPE LATCHES
WITH 3-STATE OUTPUTS
SCBS197D – FEBRUARY 1991 – REVISED MAY 1997
D State-of-the-Art EPIC-ΙΙB™ BiCMOS Design
Significantly Reduces Power Dissipation
D Latch-Up Performance Exceeds 500 mA Per
JEDEC Standard JESD-17
D Typical V_OLP (Output Ground Bounce) < 1 V
at V_CC = 5 V, T_A = 25°C
D High-Drive Outputs (–32-mA I_OH, 64-mA I_OL)
D Package Options Include Plastic
Small-Outline (DW) and Shrink
Small-Outline (DB) Packages, Ceramic Chip
Carriers (FK), Ceramic Flat (W) Package,
and Plastic (NT) and Ceramic (JT) DIPs
description
The ’ABT843 9-bit latches are designed
specifically for driving highly capacitive or
relatively low-impedance loads. They are
particularly suitable for implementing buffer
registers, I/O ports, bidirectional bus drivers, and
working registers.
SN54ABT843 . . . JT OR W PACKAGE
SN74ABT843 . . . DB, DW, OR NT PACKAGE
(TOP VIEW)
OE ¹
1D ²
2D ³
3D ⁴
4D ⁵
5D ⁶
6D ⁷
7D 8
8D 9
9D 10
CLR 11
GND 12
24 _VCC
23 _1Q
22 _2Q
21 _3Q
20 _4Q
19 _5Q
18 _6Q
17 7Q
16 8Q
15 9Q
14 PRE
13 LE
SN54ABT843 . . . FK PACKAGE
(TOP VIEW)
The nine transparent D-type latches provide true
data at the outputs.
A buffered output-enable (OE) input can be used
to place the nine outputs in either a normal logic
state (high or low logic levels) or a
high-impedance state. The outputs are also in the
high-impedance state during power-up and
power-down conditions. The outputs remain in the
high-impedance state while the device is powered
down. In the high-impedance state, the outputs
neither load nor drive the bus lines significantly.
The high-impedance state and increased drive
provide the capability to drive bus lines without
need for interface or pullup components.
4 3 2 1 28 27 26
3D 5
25 3Q
4D 6
24 4Q
5D 7
23 5Q
NC 8
22 NC
6D 9
21 6Q
7D 10
20 7Q
8D 11
19 8Q
12 13 14 15 16 17 18
NC – No internal connection
OE does not affect the internal operations of the latch. Previously stored data can be retained or new data can
be entered while the outputs are in the high-impedance state.
To ensure the high-impedance state during power up or power down, OE should be tied to V_CC through a pullup
resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
The SN54ABT843 is characterized for operation over the full military temperature range of –55°C to 125°C. The
SN74ABT843 is characterized for operation from –40°C to 85°C.
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.
EPIC-ΙΙB 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.
Copyright © 1997, Texas Instruments Incorporated
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