SN54ALS29823_15 Datasheet, PDF (1/11 Pages) Texas Instruments – 9-BIT BUS-INTERFACE FLIP-FLOPS WITH 3-STATE OUTPUTS

SN54ALS29823, SN74ALS29823
9-BIT BUS-INTERFACE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SDAS146B – JANUARY 1986 – REVISED JANUARY 1995
• Functionally Equivalent to AMD’s AM29823
• Provide Extra Data Width Necessary for
Wider Address/Data Paths or Buses With
SN54ALS29823 . . . JT PACKAGE
SN74ALS29823 . . . DW OR NT PACKAGE
(TOP VIEW)
Parity
• Outputs Have Undershoot-Protection
Circuitry
• Power-Up High-Impedance State
OE 1
1D 2
2D 3
3D 4
24 V_CC
23 1Q
22 2Q
21 3Q
• Buffered Control Inputs Reduce dc Loading
Effects
• Package Options Include Plastic
Small-Outline (DW) Packages and Standard
Plastic (NT) and Ceramic (JT) 300-mil DIPs
4D 5
5D 6
6D 7
7D 8
8D 9
9D 10
20 4Q
19 5Q
18 6Q
17 7Q
16 8Q
15 9Q
description
CLR 11
GND 12
14 CLKEN
13 CLK
These 9-bit flip-flops feature 3-state outputs
designed specifically for driving highly capacitive
or relatively low-impedance loads. They are particularly suitable for implementing wider buffer registers, I/O
ports, bidirectional bus drivers, parity bus interfacing, and working registers.
With the clock-enable (CLKEN) input low, the nine D-type edge-triggered flip-flops enter data on the low-to-high
transitions of the clock (CLK) input. Taking CLKEN high disables the clock buffer, latching the outputs. The
′ALS29823 have noninverting data (D) inputs. Taking the clear (CLR) input low causes the nine Q outputs to
go low independently of the clock.
A buffered output-enable (OE) input places the nine outputs in either a normal logic state (high or low logic levels)
or a high-impedance state. The outputs also are 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 interface or pullup components.
OE does not affect the internal operation of the flip-flops. Old data can be retained or new data can be entered
while the outputs are in the high-impedance state.
The SN54ALS29823 is characterized for operation over the full military temperature range of – 55°C to 125°C.
The SN74ALS29823 is characterized for operation from 0°C to 70°C.
FUNCTION TABLE
(each flip-flop)
INPUTS
OE CLR CLKEN CLK D
L
L
X
X
X
L
H
L
↑
H
L
H
L
↑
L
L
H
H
X
X
H
X
X
X
X
OUTPUT
Q
L
H
L
Q0
Z
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 © 1995, Texas Instruments Incorporated
1