System and method for communicating driver readiness to a controller

A method for sensing a readiness of a driver of a switching regulator, the method comprising:

• starting a controller power supply for a controller of the switching regulator;
• coupling the controller power supply to the driver of the switching regulator;
• enabling a driver power supply of the driver of the switching regulator;
• comparing a driver-supply voltage of the driver power supply to a controller-supply voltage of the controller power supply;
• powering a driver-wake circuit of the driver using a greater of the driver-supply voltage and the controller-supply voltage;
• comparing, using the driver-wake circuit, the driver-supply voltage to a power-on-reset threshold;
• configuring the driver-wake circuit to generate a short-circuit condition at a temperature-monitoring pin of the driver while the driver-supply voltage is less than a power-on-reset threshold;
• configuring the driver-wake circuit to generate an open-circuit condition at the temperature-monitoring pin of the driver while the driver-supply voltage is greater than the power-on-reset threshold;
• and
• sensing the readiness of the driver based on the short-circuit condition or the open-circuit condition of the temperature-monitoring pin.

A multiphase switching regulator comprising:

• a controller configured to receive power from a first power supply at a first supply pin and to couple the power from the first power supply to a driver-ON pin;
• a first driver coupled to the driver-ON pin via a first-driver-wake pin and coupled to a second power supply via a second-supply pin, the first driver configured to:
• receive power from the first power supply and block power from the second power supply while a second power supply voltage is less than a first power supply voltage;
• and
• a second driver coupled to the driver-ON pin via a second-driver-wake pin and coupled to a third power supply at a third-supply pin, the second driver configured to:
• receive power from the first power supply and block power from the third power supply while a third power supply voltage is less than the first power supply voltage.