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DM74LS157 • DM74LS158
Absolute Maximum Ratings(Note 1) Note 1: The “Abso lute Maximum Ratings” ar e those value s 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 tables are not guaranteed at the absolute maximum ratings.
The “Re comm ended Operat ing Co ndition s” table will de fine the cond itions
for actu al device operation.
DM74LS157 Recommended Operating Conditions
DM74LS157 Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Note 2: All typicals are at VCC = 5V, TA = 25 °C.
Note 3: N ot m ore than one output sh ould be sh orted at a tim e, and the duration sh ould not ex c eed one sec ond.
Note 4: ICC is meas ured with 4. 5V appli ed t o all input s and all outputs OPE N .
DM74LS157 Switching Characteristics
at VCC = 5V and TA = 25°C
Supply Voltage 7V
Input Voltage 7V
Operating Free Air Temperature Range 0°C to +70°C
Storage Temperature Range −65°C to +150°C
Symbol Parameter Min Nom Max Units
VCC Supply Voltage 4.75 5 5.25 V
VIH HIGH Level Input Voltage 2 V
VIL LOW Level Input Voltage 0.8 V
IOH HIGH Level Output Current −0.4 mA
IOL LOW Level Output Current 8 mA
TAFree Air Operating Te mperature 0 70 °C
Symbol Parameter Conditions Min Typ Max Units
(Note 2)
VIInput Clamp Voltage VCC = Min, II = −18 mA −1.5 V
VOH HIGH Level Output Voltage VCC = Min, IOH = Max, VIL = Max, VIH = Min 2.7 3.4 V
VOL LOW Level VCC = Min, IOL = Max, VIL = Max, VIH = Min 0.35 0.5 V
Output Voltage IOL = 4 mA, VCC = Min 0.25 0.4
IIInput Current @ Max VCC = Max S or G 0.2 mA
Input Voltage VI = 7V A or B 0.1
IIH HIGH Level VCC = Max S or G 40 µA
Input Current VI = 2.7V A or B 20
IIL LOW Level VCC = Max S or G −0.8 mA
Input Current VI = 0.4V A or B −0.4
IOS Short Circuit Output Current VCC = Max (Note 3) −20 −100 mA
ICC Supply Current VCC = Max (Note 4) 9.7 16 mA
From (Input) RL = 2 kΩ
Symbol Parameter To (Output) CL = 15 pF CL = 50 pF Units
MinMaxMinMax
tPLH Propagation Delay Time Data to Y 14 18 ns
LOW-to-HIGH Level Output
tPHL Propagation Delay Time Data to Y 14 23 ns
HIGH-to-LOW Level Output
tPLH Propagation Delay Time Strobe to Y 20 24 ns
LOW-to-HIGH Level Output
tPHL Propagation Delay Time Strobe to Y 21 30 ns
HIGH-to-LOW Level Output
tPLH Propagation Delay Time Select to Y 23 28 ns
LOW-to-HIGH Level Output
tPHL Propagation Delay Time Select to Y 27 32 ns
HIGH-to-LOW Level Output