my chip original design is need 3.3v ,
but I hope it can work from 1v~ 3.3v , we use 0.18um process
and I have idea is use "charge_pump" or "PWM power" ,
convert 1v -> 3.3v and only need 1 AAA battery in system ,
but analog chip include "charge_pump" oe PWM chip will cause many noise couple . how to reduce substrate noise couple in analog chip ?? use double guard ring ??
another way is use 1v standard cell library design , but 1v cell look like delay time is large for mp3 player , and as I know analog use 1V design more problem than 3v