High-Impedance State During Power Up
and Power Down
D
ESD Protection Exceeds 2000 V Per
MIL-STD-883, Method 3015; Exceeds 200 V
Using Machine Model (C = 200 pF, R = 0)
D
T ypical V
(Output Ground Bounce) < 1 V
OLP
at VCC = 5 V, TA = 25°C
D
Distributed VCC and GND Pin Configuration
Minimizes High-Speed Switching Noise
D
Flow-Through Architecture Optimizes
PCB Layout
D
High-Drive Outputs (–32-mA IOH,
64-mA IOL)
D
Package Options Include Plastic 300-mil
Shrink Small-Outline (DL), Thin Shrink
Small-Outline (DGG) Packages and 380-mil
Fine-Pitch Ceramic Flat (WD) Package
Using 25-mil Center-to-Center Spacings
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 ’ABT16823 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 level) or a high-impedance state. 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.
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.
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 1997, Texas Instruments Incorporated
1
Page 2
SN54ABT16823, SN74ABT16823
18-BIT BUS-INTERFACE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SCBS217C – JUNE 1992 – REVISED JANUARY 1997
description (continued)
When VCC is between 0 and 2.1 V , the device is in the high-impedance state during power up or power down.
However, to ensure the high-impedance state above 2.1 V, OE should be tied to VCC through a pullup resistor;
the minimum value of the resistor is determined by the current-sinking/current-sourcing capability of the driver.
The SN54ABT16823 is characterized for operation over the full military temperature range of –55°C to 125°C.
The SN74ABT16823 is characterized for operation from –40°C to 85°C.
FUNCTION TABLE
(each 9-bit flip-flop)
INPUTS
OE
CLRCLKEN
LLXXXL
LHL↑HH
LHL↑LL
LHLLX Q
LHHXX Q
HXXXXZ
CLKD
OUTPUT
Q
0
0
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Page 3
SN54ABT16823, SN74ABT16823
18-BIT BUS-INTERFACE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SCBS217C – JUNE 1992 – REVISED JANUARY 1997
logic symbol
†
2
1OE
1CLR
1CLKEN
1CLK
2CLR
2CLKEN
2CLK
1
55
56
27
2OE
28
30
29
54
1D11Q1
52
1D21Q2
51
1D3
49
1D4
48
1D5
47
1D6
45
1D71Q7
44
1D81Q8
43
1D91Q9
42
2D12Q1
41
2D22Q2
40
2D32Q3
38
2D42Q4
37
2D52Q5
36
2D62Q6
34
2D72Q7
33
2D8
31
2D9
EN1
R2
G3
EN5
R6
G7
4D
8D
3C4
7C8
1, 2
5, 6
10
12
13
14
15
16
17
19
20
21
23
24
26
3
5
6
1Q3
8
1Q4
9
1Q5
1Q6
2Q8
2Q9
†
This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
3
Page 4
SN54ABT16823, SN74ABT16823
18-BIT BUS-INTERFACE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SCBS217C – JUNE 1992 – REVISED JANUARY 1997
logic diagram (positive logic)
2
1OE
1CLR
1CLKEN
1CLK
2OE
2CLR
2CLKEN
2CLK
1
55
56
27
28
30
29
1D1
2D1
54
42
CE
R
C1
1D
To Eight Other Channels
CE
R
C1
1D
15
3
1Q1
2Q1
To Eight Other Channels
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Page 5
UNIT
SN54ABT16823, SN74ABT16823
18-BIT BUS-INTERFACE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SCBS217C – JUNE 1992 – REVISED JANUARY 1997
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTES: 1. The input and output negative-voltage ratings may be exceeded if the input and output clamp-current ratings are observed.
2. The package thermal impedance is calculated in accordance with EIA/JEDEC Std JESD51.
switching characteristics over recommended ranges of supply voltage and operating free-air
temperature, C
PARAMETER
f
max
t
PLH
t
PHL
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
= 50 pF (unless otherwise noted) (see Figure 1)
L
FROM
(INPUT)
CLR
TO
(OUTPUT)
Q1.94.15.31.96.3ns
SN54ABT16823SN74ABT16823
SN54ABT16823
VCC = 5 V,
TA = 25°C
MINTYPMAX
150150MHz
1.63.95.51.67.7
2.13.95.42.16.4
13.14.215.1
1.53.54.61.55.7
2.24.362.26.8
1.64.36.41.69.9
MINMAX
UNIT
ns
UNIT
switching characteristics over recommended ranges of supply voltage and operating free-air
temperature, C
PARAMETER
f
max
t
PLH
t
PHL
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
= 50 pF (unless otherwise noted) (see Figure 1)
L
FROM
(INPUT)
CLR
TO
(OUTPUT)
Q1.94.15.31.96.1ns
SN74ABT16823
VCC = 5 V,
TA = 25°C
MINTYPMAX
150150MHz
1.63.95.51.66.8
2.13.95.42.16
13.14.214.9
1.53.54.61.55.5
2.24.35.62.26.1
1.64.36.41.68.7
MINMAX
UNIT
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
7
Page 8
SN54ABT16823, SN74ABT16823
18-BIT BUS-INTERFACE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SCBS217C – JUNE 1992 – REVISED JANUARY 1997
PARAMETER MEASUREMENT INFORMATION
From Output
Under Test
CL = 50 pF
(see Note A)
Input
500 Ω
500 Ω
LOAD CIRCUIT
t
w
1.5 V1.5 V
VOLTAGE WAVEFORMS
PULSE DURATION
S1
7 V
Open
GND
3 V
0 V
Timing Input
Data Input
TESTS1
t
PLH/tPHL
t
PLZ/tPZL
t
PHZ/tPZH
t
su
1.5 V1.5 V
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
Open
Open
1.5 V
t
7 V
h
3 V
0 V
3 V
0 V
Input
t
PLH
Output
t
PHL
Output
PROPAGATION DELAY TIMES
INVERTING AND NONINVERTING OUTPUTS
NOTES: A. CL includes probe and jig capacitance.
B. Waveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control.
Waveform 2 is for an output with internal conditions such that the output is high except when disabled by the output control.
C. All input pulses are supplied by generators having the following characteristics: PRR ≤ 10 MHz, ZO = 50 Ω, tr ≤ 2.5 ns, tf≤ 2.5 ns.
D. The outputs are measured one at a time with one transition per measurement.
1.5 V1.5 V
1.5 V
1.5 V1.5 V
VOLTAGE WAVEFORMS
Figure 1. Load Circuit and Voltage Waveforms
t
PHL
1.5 V
t
PLH
3 V
0 V
V
V
V
V
OH
OL
OH
OL
Output
Control
Output
Waveform 1
S1 at 7 V
(see Note B)
Output
Waveform 2
S1 at Open
(see Note B)
1.5 V
t
PZL
t
PLZ
1.5 V
t
t
PZH
ENABLE AND DISABLE TIMES
LOW- AND HIGH-LEVEL ENABLING
PHZ
1.5 V
VOLTAGE WAVEFORMS
1.5 V
VOL + 0.3 V
VOH – 0.3 V
3 V
0 V
3.5 V
V
OL
V
OH
≈ 0 V
8
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Page 9
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pertaining to warranty, patent infringement, and limitation of liability.
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accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent
TI deems necessary to support this warranty . Specific testing of all parameters of each device is not necessarily
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DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL
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intellectual property right of TI covering or relating to any combination, machine, or process in which such
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party’s products or services does not constitute TI’s approval, warranty or endorsement thereof.
Copyright 1998, Texas Instruments Incorporated
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