SN54ABTH16823, SN74ABTH16823
18-BIT BUS-INTERFACE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SCBS664B – APRIL 1996 – REVISED MAY 1997
SN54ABTH16823 . . . WD PACKAGE
SN74ABTH16823 . . . DGG OR DL PACKAGE
(TOP VIEW)
Members of the Texas Instruments
Widebus Family
State-of-the-Art EPIC-ΙΙB BiCMOS Design
Significantly Reduces Power Dissipation
1CLR
1OE
1Q1
GND
1Q2
1Q3
1CLK
1CLKEN
1D1
GND
1D2
1
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
ESD Protection Exceeds 2000 V Per
MIL-STD-883, Method 3015; Exceeds 200 V
Using Machine Model (C = 200 pF, R = 0)
2
3
4
5
Typical V
(Output Ground Bounce) < 1 V
OLP
1D3
6
at V
= 5 V, T = 25°C
CC
A
V
V
7
CC
CC
High-Impedance State During Power Up
and Power Down
1Q4
1Q5
1Q6
GND
1Q7
1Q8
1Q9
2Q1
2Q2
2Q3
GND
2Q4
2Q5
2Q6
1D4
1D5
1D6
GND
1D7
1D8
1D9
2D1
2D2
2D3
GND
2D4
2D5
2D6
8
9
Distributed V
Minimizes High-Speed Switching Noise
and GND Pin Configuration
CC
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Flow-Through Architecture Optimizes PCB
Layout
High-Drive Outputs (–32-mA I , 64-mA I
)
OL
OH
Bus Hold on Data Inputs Eliminates the
Need for External Pullup/Pulldown
Resistors
Package Options Include Plastic 300-mil
Shrink Small-Outline (DL) and Thin Shrink
Small-Outline (DGG) Packages and 380-mil
Fine-Pitch Ceramic Flat (WD) Package
Using 25-mil Center-to-Center Spacings
V
V
CC
CC
2Q7
2Q8
GND
2Q9
2OE
2CLR
2D7
2D8
GND
2D9
2CLKEN
2CLK
description
These 18-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 with
parity, and working registers.
The ’ABTH16823 can be used as two 9-bit flip-flops or one 18-bit flip-flop. With the clock-enable (CLKEN) input
low, the D-type flip-flops enter data on the low-to-high transitions of the clock. Taking CLKEN high disables the
clock buffer, latching the outputs. Taking the clear (CLR) input low causes the Q outputs to go low independently
of the clock.
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. In the high-impedance state, the outputs neither load nor drive
thebuslinessignificantly. Thehigh-impedancestateandincreaseddriveprovidethecapabilitytodrivebuslines
without need for 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.
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.
Widebus and EPIC-ΙΙB are trademarks of Texas Instruments Incorporated.
Copyright 1997, 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.
1
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