A power supply ready indicator circuit is described. The power supply ready indicator circuit includes a first power-supply-ready-input interfacing with a first power supply rail; a second power-supply-ready-input interfacing with a second power supply rail; and a power ready indicator output. The power supply ready indicator circuit is configured to divide the voltage on the first power supply rail, and to compare the divided voltage with the second power supply rail voltage. The power supply ready indicator circuit generates a power ready signal on the power ready indicator output in response to the divided voltage value being greater than the second power supply rail voltage value. The final value of the first power supply rail voltage is greater than the final value of the second power supply rail voltage.