Test
Parameter 
Unit 
Typical
Description 
Logic High Input
Voltage,
Vih (Logic "1") 
V 
This is the
minimum voltage that an input of a CMOS digital IC is guaranteed to
recognize as a Logic "1".
Typical Spec:
3.5 V min. for Vss = 5V 
Logic Low Input
Voltage,
Vil (Logic "0") 
V 
This is the
maximum voltage that an input of a CMOS digital IC is guaranteed to
recognize as a Logic "0".
Typical Spec:
1.5 V max. for Vss = 5V 
Logic High Output
Voltage,
Voh (Logic "1") 
V 
This is the
minimum voltage that an output of a CMOS digital IC is guaranteed to
deliver as a Logic "1".
Typical Spec:
4.99 V min. for Vss = 5V 
Logic Low
Output
Voltage,
Vol
(Logic "0") 
V 
This is the
maximum voltage that an output of a CMOS digital IC is guaranteed to
deliver as a Logic "0".
Typical Spec:
0.01 V max. for Vss = 5V 
Logic High
Input Current,
Iih

pA 
This is the
minimum amount of current needed by an input of a CMOS digital IC
to stay
at Logic "1".
Example of an
Actual Spec:
+10 pA
min. when Vss = 5V; Vin =
3.5V 
Logic Low Input
Current,
Iil 
pA 
This is the
maximum amount of current
that the input of a CMOS digital IC can sink
to stay at Logic "0".
Example of an
Actual Spec:
10 pA max. when Vss = 5V; Vin =
1.5V 
Logic High
Output Current,
Ioh

mA 
This is the
maximum amount of current that an output of a CMOS digital IC
can source while
at Logic "1".
Example of an
Actual Spec:
0.5 mA
max. when Vss = 5V; Vin
= 3.5V 
Logic Low Output
Current,
Iol 
mA 
This is the
maximum amount of current that an output of a CMOS digital IC can sink
while at Logic "0".
Example of an
Actual Spec:
+0.4 mA max. when Vss = 5V; Vin
= 1.5V 