Switching regulator and control method thereof
View Patent ↗A novel method to operate a switching regulator is presented. The method includes the generation of at least two reference signals. A first reference signal is a constant DC voltage signal and a second reference signal is a periodic ramp sawtooth signal at a given frequency. It also includes the generation of a feedback signal by using the output voltage of the switching regulator. In one method, a capacitor is either charged by a bias current or discharged by a switch. A first comparator is configured to compare a first constant DC reference voltage signal to a feedback signal. A second comparator is configured to compare a periodic ramp sawtooth signal to a voltage signal on the capacitor. In an alternative method, a comparator is configured to compare the feedback signal to either the periodic ramp sawtooth reference signal or the constant DC reference signal depending on the switching operation of the switching regulator. The periodic ramp sawtooth reference signal can be either positive or negative. The method is presented for buck switching regulators, and can be utilized also for boost, buck-boost, flyback, forward, and sepic, etc.
1. A switching regulator configured to receive an input voltage and to generate a regulated output voltage; and said switching regulator controlling a high-side power switch and a low-side power switch based on a feedback control scheme to drive a switching node for generating a switching output voltage; and said switching node being coupled to an LC filter to generate said regulated output voltage on an output capacitor; and said switching regulator comprising:
a constant voltage reference signal;
a periodic ramp sawtooth reference signal at a given frequency;
wherein said periodic ramp sawtooth reference signal not being generated from said switching output voltage;
a feedback generation circuit configured to generate a first feedback signal; wherein said first feedback signal being in phase with an inductor current; wherein said first feedback signal being generated through sensing said inductor current;
a controller configured to receive said first feedback signal and said periodic ramp sawtooth reference signal and a voltage amplifier output signal;
wherein said controller comprising a first comparator; wherein comparing signals of said first comparator consisting of said first feedback signal and said voltage amplifier output signal;
wherein said controller further comprising a capacitor;
wherein said controller further comprising a first switch; wherein said capacitor being discharged through turning on said first switch;
wherein said controller further comprising a second switch: wherein said capacitor being charged through a bias current by turning on said second switch thereby generating a voltage signal on said capacitor;
wherein said controller further comprising a second comparator configured to compare said periodic ramp sawtooth reference signal and said voltage signal on said capacitor and to generate a second comparator output signal;
wherein a logic and driver circuit configured to directly receive said first comparator output signal and to directly receive said second comparator output signal and to generate control signals of said high-side power switch and said low-side power switch.
2. Said switching regulator in claim 1 , further comprising a plurality of said switching regulator circuits; wherein said plurality of said switching regulator circuits configured to be a multi-phase switching regulator.
3. Said switching regulator in claim 1 being a switching regulator belonging to a group comprising buck, boost, buck-boost, flyback, forward and sepic switching regulator.
4. A switching regulator configured to receive an input voltage and to generate a regulated output voltage; and said switching regulator controlling a high-side power switch and a low-side power switch based on a feedback control scheme to drive a switching node for generating a switching output voltage; and said switching node being coupled to an LC filter to generate said regulated output voltage on an output capacitor; and said switching regulator comprising:
a constant voltage reference signal;
a periodic ramp sawtooth reference signal at a given frequency; wherein said periodic ramp sawtooth reference signal not being generated from said switching output voltage;
a feedback generation circuit configured to generate a first feedback signal; wherein said first feedback signal being in phase with an inductor current; wherein said first feedback signal being generated through sensing said inductor current;
a controller configured to receive said first feedback signal and said periodic ramp sawtooth reference signal and said constant voltage reference signal;
wherein said controller comprising a first comparator; wherein comparing signals of said first comparator consisting of said first feedback signal and said constant voltage reference signal;
wherein said controller further comprising a capacitor;
wherein said controller further comprising a first switch; wherein said capacitor being discharged through turning on said first switch;
wherein said controller further comprising a second switch; wherein said capacitor being charged through a bias current by turning on said second switch thereby generating a voltage signal on said capacitor;
wherein said controller further comprising a second comparator configured to compare said periodic ramp sawtooth reference signal and said voltage signal on said capacitor and to generate a second comparator output signal;
wherein a logic and driver circuit configured to directly receive said first comparator output signal and to directly receive said second comparator output signal and to generate control signals of said high-side power switch and said low-side power switch.
5. Said switching regulator in claim 4 , further comprising a plurality of said switching regulator circuits; wherein said plurality of said switching regulator circuits configured to be multi-phase switching regulator.
6. Said switching regulator in claim 4 further being a switching regulator belonging to a group comprising buck, boost, buck-boost, flyback, forward and sepic switching regulator.
7. A method in a switching regulator receiving an input voltage and controlling a high-side power switch and a low-side power switch to drive a switching node for generating a switching output voltage; and said switching node being coupled to an LC filter circuit to generate a regulated output voltage on an output capacitor; said method comprising:
generating a voltage amplifier output signal;
generating a periodic ramp sawtooth reference signal at a given frequency;
wherein said periodic ramp sawtooth reference signal not being generated from said switching output voltage;
generating a first feedback signal being in phase with an inductor current; wherein said first feedback signal being generated through sensing said inductor current; receiving said voltage amplifier output signal and said first feedback signal and said periodic ramp sawtooth reference signal;
comparing said first feedback signal and said voltage amplifier output signal through a first comparator; wherein comparing signals of said first comparator consisting of said first feedback signal and said voltage amplifier output signal; generating a voltage signal on a capacitor;
discharging said capacitor through turning on a first switch;
generating said voltage signal on said capacitor by charging said capacitor through a bias current by turning on a second switch;
comparing said periodic ramp sawtooth reference signal and said voltage signal on said capacitor through a second comparator and generating a second comparator output signal;
directly receiving said first comparator output signal and said second comparator output signal through a logic and driver circuit; and generating control signals of said high-side power switch and said low-side power switch through said logic and driver circuit.
8. Said method in claim 7 , wherein said switching regulator, further comprising a plurality of said switching regulator circuits; wherein said plurality of said switching regulator circuits configured to be a multi-phase switching regulator.
9. Said method in claim 7 , wherein said switching regulator being a switching regulator belonging to a group comprising buck, boost, buck-boost, flyback, forward and sepic switching regulator.