I have a digital circuit made of several blocks. The supply voltage is not fixed and varies is time, because the circuits are current-starved. In order to check the current consumption of each block, I have put dummy voltage generators in series to the voltage supply of each block. However, this method doesn't work. Some currents are negative, indicating that the circuit is generating current. I think this strange behaviour is due on the fluctuating voltage consumption. I have put 0Ohm resistors in series, instead of voltage generators, but the problem remains. I am using spectre version 10.1.1.029.isr3 (APS mode).
Please, let me know what you think about.
Thanks a lot,
I don't know about the strange circuit behaviour, but I would recommend using an "iprobe" component in series to measure the current - this component does not add to the complexity of the simulation solution matrix (as a resistor would), so it may be the best method to measure the current. With this component the current measured is the same as that being internally calculated, the iprobe just gives visibility of it.