Control system for LLC voltage converter using up-down counter configured to react to comparator output
AssigneeTexas Instruments Incorporated
InventorsLongqi Li, Desheng Guo
Life of this patent
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Abstract
An inductor-inductor-capacitor (LLC) converter may include a control system that holds a duty cycle of control signals at a desired ratio, such as 50%. The control system may include a counter that is configured to count up and down and is further configured to generate event signals that are received at the inputs of a latch. An event signal may cause and output value of the latch to change from high to low or vice versa. There may be further circuits to add delay and/or inversion to generate multiple control signals from the output of the latch. Furthermore, the counter may be configured to switch from counting up to counting down in response to a comparator output.
Claims20
A circuit comprising:
- a comparator having a first comparator input, a second comparator input, and a comparator output;
- a latch having a first latch input, a second latch input, and a latch output;
- an up-down counter having a first input coupled to the comparator output, wherein:
- the first latch input is coupled to a first output of the up-down counter;
- the second latch input is coupled to a second output of the up-down counter;
- and
- the second latch input is coupled to the comparator output.
A voltage converter system comprising:
- an inductor-inductor-capacitor (LLC) voltage converter having a resonant capacitor and a resonant inductor;
- and
- a control circuit configured to provide a first control signal and a second control signal to the LLC voltage converter, wherein the control circuit comprises:
- a comparator configured to:
- receive a first voltage signal based on a voltage of the resonant capacitor;
- receive a second voltage signal, which is a ramp signal;
- and
- output a comparator output signal;
- an up-down counter configured to receive the comparator output signal, further wherein the up-down counter is configured to output a first event signal in response to counting a preconfigured value;
- a latch having a first latch input and a second latch input, wherein the latch is configured to receive the first event signal at the first latch input and to receive a signal based on the comparator output signal at the second latch input;
- and
- an output signal module, configured to:
- receive a latch output from the latch;
- and
- generate the first control signal and the second control signal from the latch output.
A voltage converter controller comprising:
- a comparator configured to receive a feedback signal and a ramp signal, the comparator being further configured to output a comparator output;
- a pulse width modulation (PWM) module configured to receive the comparator output and to generate a first control signal and a second control signal, wherein the PWM module is configured to:
- increment a count on an up-down counter;
- receive a signal edge on the comparator output;
- switch from incrementing the count to decrementing the count on the up-down counter in response to the signal edge on the comparator output;
- decrement the count to zero;
- generate a first event signal in response to switching from incrementing the count to decrementing the count, including providing the first event signal to a first latch input, thereby changing a latch output level;
- and
- change values of the first control signal and the second control signal in response to the latch output level.
Dependencies are inferred from the claim text.