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Part: 8413501FA
Category:
Logic
-> Encoders/Multiplexers
-> Multiplexers
Description: ti SN54ALS251, 1-Of-8 Data Selectors/multiplexers With 3-State Outputs
Company: Texas Instruments, Inc.
Datasheet: Download 8413501FA datasheet File size : 79 kB
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SN54ALS251, SN74ALS251 1-OF-8 DATA SELECTORS/MULTIPLEXERS WITH 3-STATE OUTPUTS
SDAS215A APRIL 1982 REVISED DECEMBER 1994
· · · · ·
3-State Version of the ALS151 3-State Outputs Interface Directly With System Bus Perform Parallel-to-Serial Conversion Complementary Outputs Provide True and Inverted Data Package Options Include Plastic Small-Outline (D) Packages, Ceramic Chip Carriers (FK), and Standard Plastic (N) and Ceramic (J) 300-mil DIPs
SN54ALS251 . . . J PACKAGE SN74ALS251 . . . D OR N PACKAGE (TOP VIEW)
D3 D2 D1 D0 Y W OE GND
1 2 3 4 5 6 7 8
16 15 14 13 12 11 10 9
VC C D4 D5 D6 D7 A B C
description
These data selectors/multiplexers contain full binary decoding to select one-of-eight data sources and feature controlled complementary 3-state outputs. The 3-state outputs can interface with and drive data lines of bus-organized systems. With all but one of the common outputs disabled (at the high-impedance state), the low impedance of the signal-enabled output drives the bus line to a high or low logic level. Both outputs are controlled by the output-enable (OE) input. The outputs are disabled when OE is high. The SN54ALS251 is characterized for operation over the full military temperature range of 55°C to 125°C. The SN74ALS251 is characterized for operation from 0°C to 70°C.
FUNCTION TABLE INPUTS SELECT C X L L L L H H H H B X L L H H L L H H A X L H L H L H L H OE H L L L L L L L L OUTPUTS Y Z D0 D1 D2 D3 D4 D5 D6 D7 W Z D0 D1 D2 D3 D4 D5 D6 D7 SN54ALS251 . . . FK PACKAGE (TOP VIEW)
D1 D0 NC Y W
4 5 6 7 8
3 2 1 20 19 18 17 16 15 14 9 10 11 12 13
D2 D3 NC VCC D4 D5 D6 NC D7 A
NC No internal connection
Copyright © 1994, Texas Instruments Incorporated
D0, D1, . . . D7 = the level of the respective D input
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
OE GND NC C B
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SN54ALS251, SN74ALS251 1-OF-8 DATA SELECTORS/MULTIPLEXERS WITH 3-STATE OUTPUTS
SDAS215A APRIL 1982 REVISED DECEMBER 1994
logic symbol
OE A B C D0 D1 D2 D3 D4 D5 D6 D7 7 11 10 9 4 3 2 1 15 14 13 12 2 0 1 2 3 4 5 6 7 5 6 Y W MUX EN 0 0 G7
This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12. Pin numbers shown are for the D, J, and N packages.
logic diagram (positive logic)
OE D0 7 4
D1
3
D2
2
D3 Data Inputs D4
1 5 15 6 Y W
D5
14
D6
13
D7 A Data Select (binary) B C
12 11 10 9
Pin numbers shown are for the D, J, and N packages.
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POST OFFICE BOX 655303
· DALLAS, TEXAS 75265
SN54ALS251, SN74ALS251 1-OF-8 DATA SELECTORS/MULTIPLEXERS WITH 3-STATE OUTPUTS
SDAS215A APRIL 1982 REVISED DECEMBER 1994
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Supply voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V Input voltage, VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V Voltage applied to a disabled 3-state output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 V Operating free-air temperature range, TA: SN54ALS251 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55°C to 125°C SN74ALS251 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C Storage temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65°C to 150°C
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.
recommended operating conditions
SN54ALS251 MIN VCC VIH VIL IOH IOL TA Supply voltage High-level input voltage Low-level input voltage High-level output current Low-level output current Operating free-air temperature 55 4.5 2 0.7 1 12 125 0 NOM 5 MAX 5.5 SN74ALS251 MIN 4.5 2 0.8 2.6 24 70 NOM 5 MAX 5.5 UNIT V V V mA mA °C
electrical characteristics over recommended operating free-air temperature range (unless otherwise noted)
PARAMETER VIK VOH TEST CONDITIONS CONDITIONS VCC = 4.5 V, VCC = 4.5 V to 5.5 V, VCC = 4 5 V 4.5 VCC = 4 5 V 4.5 VCC = 5.5 V, VCC = 5.5 V, VCC = 5.5 V, VCC = 5.5 V, VCC = 5.5 V, VCC = 5.5 V, Enabled Disabled VCC = 5 5 V 5.5 II = 18 mA IOH = 0.4 mA IOH = 1 mA IOH = 2.6 mA IOL = 12 mA IOL = 24 mA VO = 2.7 V VO = 0.4 V VI = 7 V VI = 2.7 V VI = 0.4 V VO = 4.5 V Inputs at GND Inputs at 4.5 V 20 7 9.4 MIN SN54ALS251 TYP MAX 1.5 VCC 2 2.4 VCC 2 3.3 2.4 0.25 0.4 20 20 0.1 20 0.1 112 10 14 30 7 9.4 3.2 0.25 0.35 0.4 0.5 20 20 0.1 20 0.1 112 10 14 V µA µA mA µA mA mA mA V MIN SN74ALS251 TYP MAX 1.5 UNIT V
VOL IOZH IOZL II IIH IIL IO§ ICC
All typical values are at VCC = 5 V, TA = 25°C. § The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS.
POST OFFICE BOX 655303
· DALLAS, TEXAS 75265
3
SN54ALS251, SN74ALS251 1-OF-8 DATA SELECTORS/MULTIPLEXERS WITH 3-STATE OUTPUTS
SDAS215A APRIL 1982 REVISED DECEMBER 1994
switching characteristics (see Figure 1)
VCC = 4.5 V to 5.5 V, CL = 50 pF, R1 = 500 , R2 = 500 , TA = MIN to MAX SN54ALS251 MIN tPLH tPHL tPLH tPHL tPLH tPHL tPLH tPHL tPZH tPZL tPZH tPZL tPZH tPZL tPZH tPZL A, B or C B, or A, B or C B, or Y W Y W Y W Y W 1 7 5 7 2 3 3 3 3 3 3 3 2 1 2 1 MAX 21 34 38 26 15 23 25 20 21 19 21 19 12 18 12 18 SN74ALS251 MIN 5 8 8 7 2 3 3 3 3 3 3 3 2 1 2 1 MAX 18 24 24 23 10 15 15 15 15 15 15 15 10 10 10 10 ns ns ns ns ns ns ns ns
PARAMETER
FROM (INPUT)
TO (OUTPUT)
UNIT
Any D Any D OE OE OE OE
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
4
POST OFFICE BOX 655303
· DALLAS, TEXAS 75265
SN54ALS251, SN74ALS251 1-OF-8 DATA SELECTORS/MULTIPLEXERS WITH 3-STATE OUTPUTS
SDAS215A APRIL 1982 REVISED DECEMBER 1994
PARAMETER MEASUREMENT INFORMATION SERIES 54ALS/74ALS AND 54AS/74AS DEVICES
7V VCC S1 RL From Output Under Test CL (see Note A) RL Test Point R1 From Output Under Test CL (see Note A) Test Point From Output Under Test CL (see Note A) R2 Test Point RL = R1 = R2
LOAD CIRCUIT FOR BI-STATE TOTEM-POLE OUTPUTS
LOAD CIRCUIT FOR OPEN-COLLECTOR OUTPUTS
LOAD CIRCUIT FOR 3-STATE OUTPUTS
Timing Input tsu Data Input 1.3 V
3.5 V 1.3 V 0.3 V th 3.5 V 1.3 V 0.3 V VOLTAGE WAVEFORMS SETUP AND HOLD TIMES
High-Level Pulse
3.5 V 1.3 V tw 1.3 V 0.3 V
Low-Level Pulse
3.5 V 1.3 V 1.3 V 0.3 V VOLTAGE WAVEFORMS PULSE DURATIONS
Output Control (low-level enabling) tPZL Waveform 1 S1 Closed (see Note B)
3.5 V 1.3 V 1.3 V 0.3 V tPLZ 1.3 V VOL 0.3 V VOH 1.3 V 0.3 V 3.5 V Input tPLH In-Phase Output 1.3 V 1.3 V 1.3 V 0.3 V tPHL VOH 1.3 V VOL tPLH VOH 1.3 V VOLTAGE WAVEFORMS PROPAGATION DELAY TIMES 1.3 V VOL
[3.5 V
tPHZ tPZH Waveform 2 S1 Open (see Note B)
tPHL Out-of-Phase Output (see Note C)
[0 V
VOLTAGE WAVEFORMS ENABLE AND DISABLE TIMES, 3-STATE 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. When measuring propagation delay items of 3-state outputs, switch S1 is open. D. All input pulses have the following characteristics: PRR 1 MHz, tr = tf = 2 ns, duty cycle = 50%. E. The outputs are measured one at a time with one transition per measurement.
Figure 1. Load Circuits and Voltage Waveforms
POST OFFICE BOX 655303
· DALLAS, TEXAS 75265
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