Adaptive minimum on time control for a switching regulator
AssigneeTexas Instruments Incorporated
InventorsJiancong Ruan, Runqin Tan
Life of this patent
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Abstract
A switching regulator includes a high side transistor coupled to an input voltage node. The switching regulator also includes a low side transistor coupled to the high side transistor at a switch node. An adaptive on-time control circuit is also included and is configured to cause the high side transistor to turn on for an adaptive period of time based on a ratio of an output voltage from the switching regulator to input voltage. The adaptive period of time is configured to occur responsive to a current through an inductor falling below a predetermined threshold.
Claims20
A circuit, comprising:
- control logic adapted to be coupled to a high side transistor and to a low side transistor, the control logic configured to produce a zero crossing signal based on an inductor current;
- and
- a control circuit coupled to the control logic, the control circuit configured to instruct the control logic to instruct the high side transistor to turn on for an adaptive period of time, the adaptive period of time based on the zero crossing signal and based on a ratio of a switching regulator output voltage to a switching regulator input voltage.
A circuit, comprising:
- a transistor having a control terminal, a first current terminal, and a second current terminal;
- a comparator having a first comparator input, a second comparator input, and a comparator output, the first comparator input coupled to the first current terminal, and the second comparator input configured to receive a signal indicative of an output voltage;
- and
- a D flip-flop having a D input and a flip-flop output, the D input configured to receive a zero crossing signal, the flip-flop output coupled to the control terminal.
A switching regulator, comprising:
- a first transistor having a first current terminal, a second current terminal, and a control terminal, the first current terminal configured to receive an input voltage;
- a second transistor having a third current terminal, a fourth current terminal, and a second control terminal, the third current terminal coupled to the second current terminal;
- an indictor having a first inductor terminal and a second inductor terminal, the first inductor terminal coupled to the second current terminal;
- control logic coupled to the first transistor and to the second transistor, the current circuit configured to produce a zero crossing signal based on a current of the inductor;
- and
- a control circuit coupled to the control logic, the control circuit configured to instruct the control logic to cause the first transistor to turn on for an adaptive period of time, the adaptive period of time based on the zero crossing signal and a ratio of an output voltage at the second inductor terminal to the input voltage.
Dependencies are inferred from the claim text.