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Details, datasheet, quote on part number:JM38510/30906BEA
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Datasheet text preview:
54LS257A DM54LS257B DM74LS257B 54LS258A DM54LS258B DM74LS258B TRI-STATE Quad 2-Data Selectors Multiplexers
June 1989
54LS257A DM54LS257B DM74LS257B 4LS258A DM54LS258B DM74LS258B TRI-STATE Quad 2-Data Selectors Multiplexers
General Description
These Schottky-clamped high-performance multiplexers feature TRI-STATE outputs that can interface directly with data lines of bus-organized systems With all but one of the common outputs disabled (at a high impedance state) the low impedance of the single enabled output will drive the bus line to a high or low logic level To minimize the possibility that two outputs will attempt to take a common bus to opposite logic levels the output enable circuitry is designed such that the output disable times are shorter than the outT put enable times his TRI-STATE output feature means that n-bit (paralleled) data selectors with up to 258 sources can be implemented for C data buses It also permits the use of standard TTL registers for data retention throughout the system
Y Y
eatures
TRI-STATE versions LS157 and LS158 with same pinouts Schottky-clamped for significant improvement in A-C performance Provides bus interface from multiple sources in highperformance systems Average propagation delay from data input 12 ns Typical power dissipation LS257B 50 mW LS258B 35 mW 5 Alternate military aerospace devices (54LS257A 4LS258A) are available Contact a National Semiconductor Sales Office Distributor for specifications
Y
Y Y
Y
F
onnection Diagrams
Dual-In-Line Package Dual-In-Line Package
TL F 6417 1
TL F 6417 2
Order Number 54LS257ADMQB 54LS257AFMQB 54LS257ALMQB DM54LS257BJ DM54LS257BW D M74LS257BM or DM74LS257BN See NS Package Number E20A J16A M16A N16E or W16A
Order Number 54LS258ADMQB 54LS258AFMQB 54LS258ALMQB DM54LS258BJ DM54LS258BW D M74LS258BM or DM74LS258BN See NS Package Number E20A J16A M16A N16E or W16A
Function Table
Inputs Output Control H L L L L Select X L L H H A X L H X X B X X X L H Output Y LS257 Z L H L H LS258 Z H L H L
H e High Level L e Low Level X e Don't Care Z e High Impedance (off)
C TRI-STATE is a registered trademark of National Semiconductor Corporation 1995 National Semiconductor Corporation TL F 6417 RRD-B30M105 Printed in U S A
Absolute Maximum Ratings (Note)
p If Military Aerospace specified devices are required lease contact the National Semiconductor Sales S Office Distributors for availability and specifications upply Voltage Input Voltage 7V 7V Note The ``Absolute Maximum Ratings'' are those values beyond which the safety of the device cannot be guaranteed The device should not be operated at these limits The parametric values defined in the ``Electrical Characteristics'' table are not guaranteed at the absolute maximum ratings T he ``Recommended Operating Conditions'' table will define the conditions for actual device operation
Operating Free Air Temperature Range R b 55 C to a 125 C DM54LS and 54LS DM74LS 0 C to a 70 C Storage Temperature Range
b 65
C to a 150 C
ecommended Operating Conditions
Symbol VCC VIH VIL IOH IOL TA Parameter Min Supply Voltage High Level Input Voltage Low Level Input Voltage High Level Output Current Low Level Output Current Free Air Operating Temperature
b 55
DM54LS257B Nom 5 Max 55 07
b1
DM74LS257B Min 4 75 2 08
b2 6
Units Max 5 25 V V V mA mA
Nom 5
45 2
12 125 0
24 70
C
'LS257B Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted) Symbol VI VOH VOL Parameter Input Clamp Voltage High Level Output Voltage Low Level Output Voltage Conditions VCC e Min II e b18 mA VCC e Min IOH e Max VIL e Max VIH e Min VCC e Min IOL e Max VIL e Max VIH e Min IOL e 12 mA VCC e Min VCC e Max VI e 7V VCC e Max VI e 2 7V VCC e Max VI e 0 4V VCC e Max VO e 2 7V VIH e Min VIL e Max VCC e Max VO e 0 4V VIH e Min VIL e Max VCC e Max (Note 2) VCC e Max (Note 3) VCC e Max (Note 3) VCC e Max (Note 3) DM54 DM74
b 20 b 20
Min
Typ (Note 1) 34 31 0 25 0 35 0 25
Max
b1 5
Units V V
DM54 DM74 DM54 DM74 DM74 Select Other Select Other Select Other
24 24
04 05 04 02 01 40 20
b0 8 b0 4
V
II IIH IIL IOZH
Input Current Input Voltage
Max
mA mA mA
High Level Input Current Low Level Input Current Off-State Output Current with High Level Output Voltage Applied Off-State Output Current with Low Level Output Voltage Applied Short Circuit Output Current Supply Current with Outputs High Supply Current with Outputs Low Supply Current with Outputs Disabled
20
mA
IOZL
b 20 b 100 b 100
mA
IOS ICCH ICCL ICCZ
mA mA mA mA
59 92 12
10 16 19
Note 1 All typicals are at VCC e 5V TA e 25 C Note 2 Not more than one output should be shorted at a time and the duration should not exceed one second ote 3 ICC is measured with all outputs open and all possible inputs grounded2while achieving the stated output conditions
'LS257B Switching Characteristics
at VCC e 5V and TA e 25 C (See Section 1 for Test Waveforms and Output Load) From (Input) To (Output) RL e 667X CL e 45 pF Min tPLH tPHL tPLH tPHL tPZH tPZL tPHZ tPLZ Propagation Delay Time Low to High Level Output Propagation Delay Time High to Low Level Output Propagation Delay Time Low to High Level Output Propagation Delay Time High to Low Level Output Output Enable Time to High Level Output Output Enable Time to Low Level Output Output Disable Time from High Level Output (Note 1) Output Disable Time from Low Level Output (Note 1) Data to Output Data to Output Select to Output Select to Output Output Control to Y Output Control to Y Output Control to Y Output Control to Y Max 18 18 28 35 15 28 26 25 CL e 150 pF Min Max 27 27 35 42 27 38 ns ns ns ns ns ns ns ns Units
Symbol
Parameter
R Note 1 CL e 5 pF
ecommended Operating Conditions
Symbol VCC VIH VIL IOH IOL TA Parameter Min Supply Voltage High Level Input Voltage Low Level Input Voltage High Level Output Current Low Level Output Current Free Air Operating Temperature
b 55
DM54LS258B Nom 5 Max 55 Min 4 75 2 07
b1
DM74LS258B Nom 5 Max 5 25
Units V V 08
b2 6
45 2
V mA mA
12 125 0
24 70
C
'LS258B Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted) Symbol VI VOH Parameter Input Clamp Voltage High Level Output Voltage Low Level Output Voltage Conditions VCC e Min II e b18 mA VCC e Min IOH e Max VIL e Max VIH e Min VCC e Min IOL e Max VIL e Max VIH e Min IOL e 12 mA VCC e Min II Input Current Input Voltage
Max
Min
Typ (Note 1)
Max
b1 5
Units V V
DM54 DM74 DM54 DM74 DM74 Select Other Select Other
24 24
34 31 0 25 0 35 0 25 04 05 04 02 01 40 20
VOL
V
VCC e Max VI e 7V VCC e Max VI e 2 7V
mA
IIH
High Level Input Current
mA
3
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