USB power control analog subsystem architecture

A universal serial bus (USB) compatible power supply device, comprising:

• a register set to store register values to program a first reference voltage and a second reference voltage;
• a central processing unit (CPU) coupled to the register set, the CPU to store the register values in the register set, wherein the CPU comprises a first input to receive a first system interrupt and a second input to receive a second system interrupt;
• and
• a power control analog subsystem coupled to the CPU and the register set, wherein the power control analog subsystem comprises:
• a programmable reference generator to generate the first reference voltage and the second reference voltage in response to the register values for multiple functions;
• a first multiplexer coupled to a first resistor divider to receive a first value of a first voltage (Vbus_in) and coupled to a second resistor divider to receive a second value of a second voltage (Vbus_c), the first multiplexer to output a first selected voltage based on the first value of Vbus_in and the second value of Vbus_c;
• a second multiplexer coupled to the first resistor divider to receive a third value of the Vbus_in and coupled to the second resistor divider to receive a fourth value of the Vbus_c, the second multiplexer to output a second selected voltage based on the third value of Vbus_in and the fourth value of Vbus_c;
• a first comparator coupled to receive the first reference voltage from the programmable reference generator and to receive the first selected voltage from the first multiplexer, wherein the first comparator is configured to output the first system interrupt to the CPU based on a first voltage condition for a first function of the multiple functions;
• and
• a second comparator coupled to receive the second reference voltage from the programmable reference generator and to receive the second selected voltage from the second multiplexer, wherein the second comparator is configured to output the second system interrupt to the CPU based on a second voltage condition that is different from the first voltage condition for a second function of the multiple functions, wherein the first system interrupt and the second system interrupt are selected from a group consisting of an under-voltage (UV) system interrupt, an over-voltage (OV) system interrupt, a voltage source system interrupt, and a Vbus monitor system interrupt.

A method comprising:

• generating, by a programmable reference generator of a power control analog subsystem of a universal serial bus (USB) compatible power supply device, a first plurality of reference voltages for multiple functions;
• receiving, by each of a plurality of multiplexers coupled to a first resistor divider and a second resistor divider, a corresponding first value of a first voltage (Vbus_in) from the first resistor divider and a corresponding second value of a second voltage (Vbus_c) from the second resistor divider, wherein the plurality of multiplexers are of the power control analog subsystem;
• outputting, by the plurality of multiplexers of the power control analog subsystem, a second plurality of reference voltages;
• receiving, by each of a plurality of comparators of the power control analog subsystem, a corresponding reference voltage of the first plurality of reference voltages from the programmable reference generator and a corresponding selected voltage of the second plurality of reference voltages from a corresponding multiplexer of the plurality of multiplexers based on the corresponding first value of the Vbus_in and the corresponding second value of the Vbus_c;
• and
• outputting, by each of the plurality of comparators, a corresponding system interrupt based on a corresponding voltage condition for a corresponding function of the multiple functions, wherein the corresponding system interrupt comprises one or more of an under-voltage (UV) system interrupt, an over-voltage (OV) system interrupt, a voltage source system interrupt, or a Vbus monitor system interrupt.