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US 6,486,645 B1Granted
Voltage regulation circuit and related methods having a dynamically determined minimum discharge time
AssigneeSipex Corporation
InventorJeffery B. Van Auken
Life of this patent
Estimating the term…
Abstract
A circuit and method for providing a regulated output voltage. In one embodiment, the circuit includes a feedback comparator, a latch module, a switch, a current limit module and a pulse module. The pulse module generates an off-time signal that is substantially proportional to the reciprocal of the difference of the output voltage and a supply voltage. In another aspect, the method includes the step of comparing the output voltage and a reference voltage, and comparing an inductor current and a reference current. Additionally, the method includes the step of charging the inductor in response to the comparisons, and discharging the inductor for a minimum period of time if the inductor current increase to substantially equal the reference current.
Claims23
A voltage regulation circuit comprising:
- a feedback comparator having a feedback comparator first input terminal configured to receive a regulated output voltage, a feedback comparator second input terminal configured to receive a first reference voltage and a feedback comparator output terminal, said feedback comparator generating a comparison signal at said feedback comparator output terminal in response to said regulated output voltage;
- a latch module comprising a latch first input terminal in communication with said feedback comparator output terminal, a latch second input terminal configured to receive an off-time signal having a variable asserted duration, and a latch output terminal, said latch module generating a charge signal at said latch output terminal in response to said comparison signal and said off-time signal;
- a switch having a control terminal in communication with said latch output terminal, a first terminal configured to receive a current level signal, and a second terminal configured to receive a second reference voltage;
- a current limit module comprising a current limit first input terminal in communication with said latch output terminal, a current limit second input terminal configured to receive said current-level signal, a current limit third input terminal configured to receive said regulated output voltage, and a current limit output terminal, said current limit module generating a peak detect signal at said current limit output terminal in response to said charge signal, said regulated output voltage, and said current-level signal;
- and
- a pulse module comprising a pulse first input terminal in communication with said current limit output terminal, a pulse second input terminal configured to receive a supply voltage, a pulse third input terminal configured to receive said regulated output voltage, and a pulse output terminal in communication with said latch second input terminal, said pulse module generating said off-time signal at said pulse output terminal in response to said peak detect signal, said input voltage and said regulated output voltage.
3 more elements
A circuit for providing a regulated output voltage comprising:
- a feedback comparator having a feedback comparator first input terminal configured to receive a regulated output voltage, a feedback comparator second input terminal configured to receive a reference voltage and a feedback comparator output terminal, said feedback comparator providing a comparison signal at said feedback comparator output terminal in response to said regulated output voltage;
- a pulse generation module having a pulse output terminal, said pulse generation module providing an off-time signal having a first state at said pulse output terminal, said first state having a dynamically determined duration;
- and
- a logic module comprising a first logic terminal in communication with said feedback comparator output terminal, a second logic terminal in communication with said pulse output terminal, and a charge control terminal, said logic module providing a charge signal for a maximum time at said charge control terminal in response to said comparison signal and said off-time signal.
1 more element
A method for generating a regulated output voltage comprising:
- comparing said regulated output voltage and a reference voltage;
- comparing an inductor current and a reference current;
- charging an inductor for a maximum time if said regulated output voltage is less than said reference voltage and if said inductor current is less than said reference current;
- discharging said inductor for at least a minimum time if said inductor current increases to substantially equal said reference current.
1 more element
A method for generating a regulated output voltage comprising:
- generating an off-time signal having a first state and a second state, said first state having an asserted duration;
- charging an inductor for a maximum time if said regulated output voltage is less than a reference voltage and said off-time signal is not in said first state;
- and
- interrupting said charging of said inductor for at least said asserted duration if said off-time signal transitions from said second state to said first state.
1 more element
A circuit for generating a regulated output voltage comprising:
- means for detecting a peak-current limit and generating a peak-current signal in response thereto;
- means for generating an off-time signal having a variable asserted duration in response to said peak-current signal;
- means for comparing said regulated output voltage and a reference voltage and generating a comparison signal in response thereto;
- and
- means for generating a charge signal having a maximum time in response to said comparison signal and said off-time signal.
2 more elements
A circuit for generating a regulated output voltage comprising:
- means for generating an off-time signal having a first state with an asserted duration and a second state;
- means for determining a regulated output voltage;
- means for charging an inductor for a maximum time if said regulated output voltage is less than a reference voltage and said off-time signal is not in said first state;
- and
- means for interrupting said charging of said inductor for at least said asserted duration if said off-time signal transitions from said second state to said first state.
2 more elements
Dependencies are inferred from the claim text.