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Design >> Analog Design >> TSMC 65nm General Purpose ( CRN65GP) and Low power ( CRN65LP) vdd question.
https://designers-guide.org/forum/YaBB.pl?num=1468994698

Message started by tenso on Jul 19^th, 2016, 11:04pm

Title: TSMC 65nm General Purpose ( CRN65GP) and Low power ( CRN65LP) vdd question.
Post by tenso on Jul 19^th, 2016, 11:04pm

TSMC's 65nm process comes in two flavors for mixed signal and RF design, general purpose and low power. On CMC's website it says that the low power has vdd of 1.2V/2.5V

https://www.cmc.ca/WhatWeOffer/Products/CMC-00131-53461.aspx

and the general purpose has a vdd of 1V/2.5V.

https://www.cmc.ca/en/WhatWeOffer/Products/CMC-00200-01409.aspx

so my questions are (and they might be stupid ones)

- Why is the vdd higher for the low power version ( 1.2 V) versus the general purpose version ( 1 V)?
- What is the difference between the core voltage and the I/O voltage ( which is 2.5V for both)? Are we talking about the supply voltages for the transistors connected to the bond pads?

Title: Re: TSMC 65nm General Purpose ( CRN65GP) and Low power ( CRN65LP) vdd question.
Post by vroy_92 on Jul 20^th, 2016, 1:56am

I am not able to access the link you have provided.
Core voltage is a lower voltage on which mostly your digital stuff runs on and some analog parts (although the trend is to use as much as lower voltage as possible in the analog domain as well). But there are limitations on how much you can go to a lower voltage to make something functional.
For higher supply voltage, the Vth of the MOS will be higher as well (thicker oxide is used). This higher voltage MOSes are almost exclusively used in analog domain.

Title: Re: TSMC 65nm General Purpose ( CRN65GP) and Low power ( CRN65LP) vdd question.
Post by tenso on Jul 20^th, 2016, 8:40am

vroy_92 wrote on Jul 20^th, 2016, 1:56am:

I have fixed the links. Thanks for the answer regarding core voltages. Why is Vdd lower for the general purpose version (1V) than the low power version (1.2V)?