Single comparator based comparison of an input voltage against multiple reference voltages

A power stage of a switching converter comprising:

• a high-side switch and a low-side switch coupled in series between a supply source and a constant reference potential, said supply source providing an input voltage, said high-side switch and said low-side switch respectively operated by a first drive signal and a second drive signal, said first drive signal and said second drive signal to be respectively ON to drive respective currents through an inductor in a first interval and a second interval;
• a gate driver to generate said first drive signal and said second drive signal based on a control signal received from a phase controller, wherein said control signal is received with a first logic level in said first interval and with a second logic level in said second interval;
• and
• a voltage-sense block comprising:
• a comparator to compare a comparator input with a comparator reference and generate a comparator output, said comparator output to have a first output value when said comparator input is less than said comparator reference and a second output value otherwise;
• a mode selector to generate as a mode value, a first logic value if said input voltage is below a mid-voltage and a second logic value otherwise, wherein said mid-voltage is between a first reference voltage and a second reference voltage of interest, wherein said first reference voltage is lower than said second reference voltage;
• a first branch coupled to receive said input voltage at a first node, and generate a first voltage drop relative to said input voltage at a second node, wherein said first voltage drop approximately equals a difference between said first reference voltage and said comparator reference;
• a second branch coupled to receive said input voltage at said first node, and generate a second voltage drop relative to said input voltage at a third node, wherein said second voltage drop approximately equals a difference between said second reference voltage and said comparator reference;
• and
• a switching circuit to couple one of said second node or said third node as said comparator input according to said mode value,
• wherein said mode value indicates whether said comparator output represents comparison with respect to said first reference voltage or said second reference voltage, and said comparator output indicates whether said input voltage is above or below the specific reference voltage thus compared.