General Test Parameters for TTL Devices           

       

   

Test Parameter Unit

Typical Description

Logic High Input Voltage, Vih (Logic "1")

V

This is the minimum voltage that an input of a TTL digital IC is guaranteed to recognize as a Logic "1".

Standard Spec: 2.0 V min.

Logic Low Input Voltage, Vil (Logic "0")

V

This is the maximum voltage that an input of a TTL digital IC is guaranteed to recognize as a Logic "0".

Standard Spec: 0.8 V max.

Logic High Output Voltage, Voh (Logic "1")

V

This is the minimum voltage that an output of a TTL digital IC is guaranteed to deliver as a Logic "1".

Standard Spec: 2.4 V min.

Logic Low Output Voltage, Vol (Logic "0")

V

This is the maximum voltage that an output of a TTL digital IC is guaranteed to deliver as a Logic "0".

Standard Spec: 0.4 V max.

Logic High Input Current, Iih

 

A

This is the minimum amount of current needed by an input of a TTL digital IC to stay at Logic "1".

Example of an Actual Spec:

50 A min. when Vcc=Max; Vin = 2.7V

Logic Low Input Current, Iil  

 

mA

This is the maximum amount of current that the input of a TTL digital IC can sink to stay at Logic "0".

Example of an Actual Spec:

-1.6 mA max. when Vcc=max; Vin = 0.5V

Output Short Circuit Current, Ios

mA

This is the amount of current that a short-circuited TTL digital output exhibits or can handle.

Example of an Actual Spec:

-40 mA min., -65 mA typ., -100 mA max. when Vcc=max; Vout = 0V

Supply Current, Icc

mA

This is the Vcc supply current exhibited by a TTL IC.

Example of an Actual Spec:

30 mA min., 50 mA max. when Vcc=max

 

 

   

See also:   What is TTL? Logic GatesCMOS Test Parameters

                     

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