Hi
my friend told me , he ever design a RC osc use nmos cap , but
real chip have bug on oscillator frequency will drift ..they someone told him , in N_well CMOS process only use pmos , becuase oscillator
charge Vcc from 0~ vcc , when Vcc < Vth nmos cap value will have problem ..
but him say , this chip use hspice simulation is ok .. why hspice can not find this problem ?