Dependence of current from supply on the output cap

[Sambhav_1]

Hi,

In case of chain of inverters, which will be more dominant in deciding the current from power supply,the device strength or the output load. Considering, device strength and output load as two variable is this problem.

Regards.

 

[Carry for cents bazar]

Hi Akshaay


The term "device strength" is not very clear to me. Can you please explain your question and if possible post a circuit.

 

[Sambhav_1]

Hi Akshaay


The term "device strength" is not very clear to me. Can you please explain your question and if possible post a circuit.

With device strength, i mean that the W/L values in old and new technologies are same but the id has been increased due to dec. in vt, that means now it can drive the load more strongly as compared to the on in previous technology.
Schematic is a level shifter followed by 5 inverters

 

[vivekroy]

Current from the power supply for charging a capacitor at the output of an inverter=f*C*Vdd.
with scaling, Vdd drops and so does the capacitance (assuming you are using minimum W/L for all technologies), so the current drops. Your increase in Ion means you can switch faster but you have not mentioned any change in frequenc.

 

[Sambhav_1]

Current from the power supply for charging a capacitor at the output of an inverter=f*C*Vdd.
with scaling, Vdd drops and so does the capacitance (assuming you are using minimum W/L for all technologies), so the current drops. Your increase in Ion means you can switch faster but you have not mentioned any change in frequenc.

Thanks vivekroy, The operating frequency remains same