Constant time controller and controlling method for a switching regulator

摘要

In one embodiment, a controlling method for a switching regulator, can include: (i) detecting an output voltage and an inductor current of the switching regulator; (ii) determining if there is a transient change on a load of the switching regulator by using the output voltage and a first reference voltage; (iii) generating a control signal using the output voltage, the inductor current, and a second reference voltage; (iv) controlling a switch of the switching regulator to maintain the output voltage substantially constant when no transient change is determined on the load; and (v) deactivating the control signal to keep the inductor current changing along with a variation tendency of an output current of the switching regulator when a transient change is determined on the load.

主权项

1. A method of controlling a switching regulator, the method comprising:
a) detecting an output voltage and an inductor current of said switching regulator; b) determining if there is a transient change on a load of said switching regulator by using said output voltage and a first reference voltage; c) generating a control signal using said output voltage, said inductor current, and a second reference voltage; d) controlling, by said control signal having a constant pulse width according to a constant time generator configured to support a constant on-time control mode and a constant off-time control mode, a switch of said switching regulator to maintain said output voltage as substantially constant when no transient change is determined on said load; and e) deactivating said control signal by reducing said constant pulse width for a present switching cycle such that said inductor current changes along with a variation tendency of an output current of said switching regulator when a transient change whereby said output voltage transitions from a first voltage to a second voltage is determined on said load, wherein said second voltage is higher than said first voltage for said constant on-time control mode, and said second voltage is lower than said first voltage for said constant off-time control mode.