A power supply that is capable of supplying power to an input/output channel for an Industrial Process Control System. The power supply includes a primary voltage converter having a first voltage input and a second voltage output, and overvoltage protection components that prevent the second voltage from rising above a predetermined maximum. The power supply includes a first low dropout regulator that is connected to receive the second voltage and to generate a third voltage, a second low dropout regulator that is connected to receive the second voltage and to generate a fourth voltage, and a third low dropout regulator that is connected to receive the fourth voltage and to generate a fifth voltage. The power supply provides an over-voltage fault tolerant self-testable architecture, allows for compact low cost individual channel isolation and fault tolerant EMI/RFI filtration.