what are the meaning of parameters in HC types

[liuyying]

what are the meaning of parameters in HC types in datasheet of CD54HC283, CD74HC283, CD54HCT283, CD74HCT283?
I means what is VIH, VIL, VOH, VOL,Ii and Icc???

 

[abhichaotic]

HC means CMOS logic. It means these IC's are using CMOS logic. All the parameters which you are asking will be easily available in any CMOS design book under CMOS inverter topic.

 

[adriancm5]

You can easily find the definitions for those parameters if you look at the datasheet for the part.

VIH: High level for input voltage or input logic '1'
VOH: High level for output voltage or output logic '1'
VIL: Low level for input voltage or input logic '0'
VOL: Low level for output voltage or output logic '0'

The output voltage levels will depend in the type of logic that you are using, CMOS or TTL

Il: input leakage current
Icc: quiescent device current

The difference between HC and HCT parts is the power supply voltage of the parts.
HC from 2V to 6V
HCT from 4.5V to 5.5V

 

[liuyying]

then what are they represent for????
i mean what use for them???

 

[adriancm5]

I'm not sure what is your doubt. But the difference for choosing a HC part or a HCT part depends in what input logic levels do you have. As an example if my logic leves are 3.3V for logic '1' and 0V for logic '0', then I would use the HC part. But if my logic is 5V for logic '1' then it would be more useful to use the HCT for more accuracy. The idea to have different input logic levels is that you can cover a broader number of applications and logic level standars.