dear all
I have designed a biasing reference current by adding PTAT and CTAT currents together. the result is a biasing current with small temperature coefficient.
However, since both the PTA and CTAT has R in their equations, the total current still depending on the process variation. not like the bandgap reference voltage where no R in the voltage equation
Kindly, there is a process independent biasing current circuit as the case of the bandgap voltage circuit ???