Measured effectiveness of deep N-well substrate isolation in a 65 nm pixel readout chip prototype

Abstract The same charge sensitive preamplifier and discriminator circuit with different isolation strategies has been tested to compare the isolation of both analog and digital circuits from the substrate of a 65 nm bulk CMOS process to the isolation of only digital circuits, tying analog ground locally to the substrate. This study will show that the circuit with analog on the substrate and digital in deep N-well has better noise isolation between analog and digital.