DC-DC converter controller having optimized load transient response and method
AssigneeSemiconductor Components Industries, LLC
InventorsJose M. Capilla, Olivier Causse
Life of this patent
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Abstract
A power supply controller (25) is configured to accurately adjust the value of an output voltage of a power supply system (10) responsively to the output voltage increasing to an undesirable value. The controller (25) accurately limits an upper value of the output voltage during a light load condition, and rapidly reduces the value of the output voltage to a desired value. The power supply controller is configured to turn off the first output transistor but inhibit turning off the second output transistor using two different control signals.
Claims10
A method of forming a power supply controller comprising:
- configuring the power supply controller to form a drive signal having switching cycles that are used to control a first switch and a second switch to regulate an output voltage to a first value wherein a cycle includes enabling and disabling the first switch during each switching cycle and also includes enabling the second switch during each switching cycle;
- configuring a first control circuit of the power supply controller to set a first state of a first control signal responsively to a second value of the output voltage that is greater than the first value and responsively inhibit subsequent switching cycles of the power supply controller;
- and
- configuring a second control circuit to turn the first switch off and not turn the second switch off responsively to inhibiting the subsequent switching cycles during at least a portion of time that the subsequent switching cycles are inhibited.
A method of forming a power supply controller comprising:
- configuring the power supply controller to control a first switch and a second switch to regulate an output voltage to a first value, the first switch including a first transistor;
- configuring a first control circuit of the power supply controller to set a first state of a first control signal responsively to a second value of the output voltage that is greater than the first value and responsively inhibit subsequent switching cycles of the power supply controller;
- and
- configuring a second control circuit to turn the first switch off and not turn the second switch off during at least a portion of time that the subsequent switching cycles are inhibited;
- and
- selectively coupling a second transistor as the second switch in a first current mirror configuration with a third transistor to control a first current through the second switch and selectively coupling the first current mirror to receive a second current and force the first current to be a ratio of the second current.
A method of forming a power supply controller comprising:
- configuring the power supply controller to control a first switch and a second switch to regulate an output voltage to a first value, the first switch including a first transistor;
- configuring a first control circuit of the power supply controller to set a first state of a first control signal responsively to a second value of the output voltage that is greater than the first value and responsively inhibit subsequent switching cycles of the power supply controller;
- and
- configuring a second control circuit to turn the first switch off and not turn the second switch off during at least a portion of time that the subsequent switching cycles are inhibited;
- and
- selectively coupling a second transistor as the second switch in a first current mirror configuration with a third transistor to control a first current through the second switch including coupling a fourth transistor to selectively couple a control electrode of the third transistor to a first current carrying electrode of the third transistor, to a control electrode of the second transistor and to receive a second current from a second current mirror.
Dependencies are inferred from the claim text.