Small-Outline (DW) Packages, Ceramic
Chip Carriers (FK), and Plastic (NT) and
Ceramic (JT) DIPs
description
These dual 4-bit D-type latches feature 3-state
outputs designed specifically for bus driving.
These devices are particularly suitable for
implementing buffer registers, I/O ports,
bidirectional bus drivers, and working registers.
The dual 4-bit latches are transparent D-type
latches. While the latch-enable (LE) input is high,
the Q outputs follow the data (D) inputs in true
form, according to the function table. When LE is
low, the outputs are latched. When the clear (CLR
input goes low, the Q outputs go low
independently of LE. The outputs are in the
high-impedance state when the output-enable
(OE
) input is at a high logic level.
The SN54ALS873B and SN54AS873A are
characterized for operation over the full military
temperature range of –55°C to 125°C. The
SN74ALS873B and SN74AS873A are
characterized for operation from 0°C to 70°C.
SN54ALS873B, SN54AS873A . . . JT PACKAGE
SN74ALS873B, SN74AS873A . . . DW OR NT PACKAGE
SN54ALS873B, SN54AS873A . . . FK PACKAGE
1CLR
1OE
1D1
1D2
1D3
1D4
2D1
2D2
2D3
2D4
2OE
GND
(TOP VIEW)
1
24
2
23
3
22
4
21
5
20
6
19
7
18
8
17
9
16
10
15
11
14
12
13
(TOP VIEW)
V
CC
1LE
1Q1
1Q2
1Q3
1Q4
2Q1
2Q2
2Q3
2Q4
2LE
2CLR
)
CC
V
1CLRNC1LE
1Q1
25
24
23
22
21
20
19
1Q2
1Q3
1Q4
NC
2Q1
2Q2
2Q3
1D2
1D3
1D4
NC
2D1
2D2
2D3
1D1
1OE
3212827
426
5
6
7
8
9
10
11
12 13
14 15 16 17 18
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.
NC – No internal connection
FUNCTION TABLE
(each latch)
INPUTS
OE
CLR
LLXXL
LHHH H
LHHLL
LHLX Q
HXXX Z
LED
OUTPUT
Q
0
NC
2D4
2OE
GND
Copyright 1995, Texas Instruments Incorporated
2LE
2CLR
2Q4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
1
SN54ALS873B, SN54AS873A, SN74ALS873B, SN74AS873A
UNIT
DUAL 4-BIT D-TYPE LATCHES
WITH 3-STATE OUTPUTS
SDAS036D – APRIL 1982 – REVISED AUGUST 1995
logic symbol
2
1OE
23
1LE
1CLR
2CLR
†
Pin numbers shown are for the DW, JT, and NT packages.
1
3
1D1
4
1D2
5
1D3
6
1D4
11
2OE
14
2LE
13
7
2D1
8
2D2
9
2D3
10
2D4
This symbol is in accordance with ANSI/IEEE Std 91-1984 and
IEC Publication 617-12.
†
EN
C1
C
1D
EN
C1
C
1D
22
21
20
19
18
17
16
15
1Q1
1Q2
1Q3
1Q4
2Q1
2Q2
2Q3
2Q4
logic diagram (each quad latch, positive logic)
OE
LE
CLR
R
D1
D2
D3
D4
C1
1D
R
C1
1D
R
C1
1D
R
C1
1D
Q1
Q2
Q3
Q4
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.
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.
timing requirements over recommended ranges of supply voltage and operating free-air
temperature (unless otherwise noted) (see Figure 1)
SN54AS873A SN74AS873A
MINMAXMINMAX
*
tsu*
th*Hold time, data after LE↓4.54.5ns
* On products compliant to MIL-STD-883, Class B, this parameter is based on characterization data but is not production tested.
Setup time, data before LE↓
CLR low55
LE high65
22ns
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
5
SN54ALS873B, SN54AS873A, SN74ALS873B, SN74AS873A
D
Q
ns
LE
Q
ns
OE
Q
ns
OE
Q
ns
DUAL 4-BIT D-TYPE LATCHES
WITH 3-STATE OUTPUTS
SDAS036D – APRIL 1982 – REVISED AUGUST 1995
switching characteristics (see Figure 1)
VCC = 4.5 V to 5.5 V,
CL = 50 pF,
PARAMETER
t
PLH
t
PHL
t
PLH
t
PHL
t
PHL
t
PZH
t
PZL
t
PHZ
t
†
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
PLZ
FROM
(INPUT)
CLRQ310.539ns
TO
(OUTPUT)
R1 = 500 Ω,
R2 = 500 Ω,
TA = MIN to MAX
SN54AS873A SN74AS873A
MINMAXMINMAX
312.539.5
38.537.5
615.5613
4947.5
2826.5
411410.5
2827.5
28.527.5
†
UNIT
6
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
SN54ALS873B, SN54AS873A, SN74ALS873B, SN74AS873A
DUAL 4-BIT D-TYPE LATCHES
SDAS036D – APRIL 1982 – REVISED AUGUST 1995
PARAMETER MEASUREMENT INFORMATION
WITH 3-STATE OUTPUTS
From Output
Under Test
(see Note A)
LOAD CIRCUIT FOR 3-STATE OUTPUTS
Timing
Input
Data
Input
Input
In-Phase
Output
Out-of-Phase
Output
7 V
Open
S1
R1 = 500 Ω
CL = 50 pF
1.3 V
t
su
1.3 V
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
1.3 V
t
PLH
t
PHL
1.3 V1.3 V
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
Test Point
R2 = 500 Ω
t
h
1.3 V
1.3 V
1.3 V1.3 V
3.5 V
0.3 V
3.5 V
0.3 V
t
PHL
t
PLH
3.5 V
0.3 V
V
OH
V
OL
V
OH
V
OL
High-Level
Pulse
Low-Level
Pulse
Output
Control
Waveform 1
S1 Closed
(see Note B)
Waveform 2
S1 Open
(see Note B)
ENABLE AND DISABLE TIMES, 3-STATE OUTPUTS
SWITCH POSITION TABLE
TESTS1
t
PLH
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
1.3 V
1.3 V
VOLTAGE WAVEFORMS
PULSE DURATION
1.3 V
t
PZL
1.3 V
t
t
PZH
VOLTAGE WAVEFORMS
PHZ
1.3 V
t
w
Open
Open
Open
Closed
Open
Closed
1.3 V
1.3 V
1.3 V
t
PLZ
V
0.3 V
3.5 V
0.3 V
3.5 V
0.3 V
3.5 V
0.3 V
3.5 V
OL
0.3 V
V
OH
0 V
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 ≤ 1 MHz, ZO = 50 Ω, tr ≤ 2 ns, tf≤ 2 ns.
D. The outputs are measured one at a time with one transition per measurement.
Figure 1. Load Circuit and Voltage Waveforms
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
7
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.
CERT AIN APPLICATIONS USING SEMICONDUCTOR 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
Loading...
+ hidden pages
You need points to download manuals.
1 point = 1 manual.
You can buy points or you can get point for every manual you upload.