High-Impedance State During Power Up
and Power Down
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
Package Options Include Plastic 300-mil
Shrink Small-Outline (DL) Package and
380-mil Fine-Pitch Ceramic Flat (WD)
Package Using 25-mil Center-to-Center
Spacings
description
These 18-bit bus-interface 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 ’ABT162823A can be used as two 9-bit
flip-flops or one 18-bit flip-flop. With the
clock-enable (CLKEN
flip-flops enter data on the low-to-high transitions
of the clock. Taking CLKEN high disables the
clock buffer , thus latching the outputs. Taking the
clear (CLR
A buffered output-enable (OE) input places the nine outputs in either a normal logic state (high or low 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
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 outputs, which are designed to source or sink up to 12 mA, include equivalent 25-Ω series resistors to
reduce overshoot and undershoot.
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.
UNLESS OTHERWISE NOTED this document contains PRODUCTION
DATA information 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
SN54ABT162823A, SN74ABT162823A
18-BIT BUS-INTERFACE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SCBS666A – JULY 1996 – REVISED MAY 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 capability of the driver.
The SN54ABT162823A is characterized for operation over the full military temperature range of –55°C to
125°C. The SN74ABT162823A 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
SN54ABT162823A, SN74ABT162823A
18-BIT BUS-INTERFACE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SCBS666A – JULY 1996 – REVISED MAY 1997
logic symbol
†
2
1OE
1CLR
1CLKEN
1CLK3C4
2CLR
2CLKEN
2CLK
1
55
56
27
2OE
28
30
29
54
1D11Q1
52
1D21Q2
51
1D31Q3
49
1D4
48
1D5
47
1D6
45
1D7
44
1D8
43
1D91Q9
42
2D12Q1
41
2D2
40
2D32Q3
38
2D4
37
2D5
36
2D6
34
2D72Q7
33
2D82Q8
31
2D92Q9
EN1
R2
G3
EN5
R6
G7
4D
8D
7C8
1, 2
5, 6
10
12
13
14
15
16
17
19
20
21
23
24
26
3
5
6
8
1Q4
9
1Q5
1Q6
1Q7
1Q8
2Q2
2Q4
2Q5
2Q6
†
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
SN54ABT162823A, SN74ABT162823A
18-BIT BUS-INTERFACE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SCBS666A – JULY 1996 – REVISED MAY 1997
logic diagram (positive logic)
2
1OE
1
1CLR
1CLKEN
1CLK
1D1
2OE
2CLR
2CLKEN
2CLK
2D1
55
56
54
27
28
30
29
42
CE
R
C1
1D
To Eight Other Channels
CE
R
C1
1D
To Eight Other Channels
15
3
1Q1
2Q1
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Voltage range applied to any output in the high or power-off state, VO –0.5 V to 5.5 V. . . . . . . . . . . . . . . . . . .
Current into any output in the low state, I
Input clamp current, I
Output clamp current, I
Package thermal impedance, θ
Storage temperature range, T
†
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 JESD 51, except through-hole packages, which use a trace length
of zero.
PRODUCT PREVIEW information concerns products in the formative or
design phase of development. Characteristic data and other
specifications are design goals. Texas Instruments reserves the right to
change or discontinue these products without notice.
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
5
Page 6
SN54ABT162823A, SN74ABT162823A
twPulse duration
ns
t
Hold ti
CLK↑
ns
(INPUT)
(OUTPUT)
CLK
Q
ns
OE
Q
ns
OE
Q
ns
18-BIT BUS-INTERFACE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SCBS666A – JULY 1996 – REVISED MAY 1997
timing requirements over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (see Figure 1)
VCC = 5 V,
TA = 25°C
MINMAXMINMAXMINMAX
f
clock
t
su
h
Clock frequency015001500150MHz
CLR low3.33.33.3
CLK high or low3.33.33.3
CLR inactive1.621.6
Setup time before CLK↑
me after
Data
CLKEN low2.82.82.8
Data1.21.21.2
CLKEN low0.60.60.6
222
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
CLR
TO
Q2.856.32.87.22.87ns
VCC = 5 V,
TA = 25°C
MINTYPMAXMINMAXMINMAX
150150150MHz
2.34.66.22.38.42.37.5
2.84.66.12.87.12.86.7
1.73.851.75.81.75.9
356.137.237
2.64.86.12.67.32.66.6
1.94.66.71.910.21.99
SN54ABT162823A SN74ABT162823A
SN54ABT162823A SN74ABT162823A
UNIT
ns
UNIT
UNLESS OTHERWISE NOTED this document contains PRODUCTION
DATA information 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.
6
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Page 7
SN54ABT162823A, SN74ABT162823A
18-BIT BUS-INTERFACE FLIP-FLOPS
WITH 3-STATE OUTPUTS
SCBS666A – JULY 1996 – REVISED MAY 1997
PARAMETER MEASUREMENT INFORMATION
500 Ω
t
w
1.5 V
500 Ω
1.5 V
1.5 V1.5 V
From Output
Under Test
CL = 50 pF
(see Note A)
LOAD CIRCUIT
Input
Input
Output
Output
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 V
VOLTAGE WAVEFORMS
PULSE DURATION
1.5 V1.5 V
t
PLH
t
PHL
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
S1
t
PHL
1.5 V
t
PLH
3 V
0 V
V
V
V
V
7 V
OH
OL
OH
OL
Open
GND
3 V
0 V
Timing Input
Data Input
Output
Control
Output
Waveform 1
S1 at 7 V
(see Note B)
Output
Waveform 2
S1 at Open
(see Note B)
TESTS1
t
PLH/tPHL
t
PLZ/tPZL
t
PHZ/tPZH
t
su
1.5 V1.5 V
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
t
PZL
t
PLZ
1.5 V
t
t
PZH
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES
LOW- AND HIGH-LEVEL ENABLING
PHZ
1.5 V
Open
Open
1.5 V
t
7 V
h
1.5 V1.5 V
VOL + 0.3 V
VOH – 0.3 V
3 V
0 V
3 V
0 V
3 V
0 V
3.5 V
V
OL
V
OH
≈ 0 V
Figure 1. Load Circuit and Voltage Waveforms
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
7
Page 8
IMPORTANT NOTICE
T exas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue
any product or service without notice, and advise customers to obtain the latest version of relevant information
to verify, before placing orders, that information being relied on is current and complete. All products are sold
subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those
pertaining to warranty, patent infringement, and limitation of liability.
TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in
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
performed, except those mandated by government requirements.
CERTAIN APPLICA TIONS USING SEMICONDUCT OR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF
DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL
APPLICATIONS”). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR
WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER
CRITICAL APPLICA TIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERST OOD TO
BE FULLY AT THE CUSTOMER’S RISK.
In order to minimize risks associated with the customer’s applications, adequate design and operating
safeguards must be provided by the customer to minimize inherent or procedural hazards.
TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent
that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other
intellectual property right of TI covering or relating to any combination, machine, or process in which such
semiconductor products or services might be or are used. TI’s publication of information regarding any third
party’s products or services does not constitute TI’s approval, warranty or endorsement thereof.
Copyright 1998, Texas Instruments Incorporated
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