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US 8,044,648 B1Granted
Start mode in switching regulation
AssigneeVolterra Semiconductor Corporation
InventorsSeth Kahn, Aaron M. Schultz
Life of this patent
Estimating the term…
Abstract
A voltage regulator is operated by, during a finite period of a voltage regular start mode having a plurality of current pulses, monotonically increasing the maximum current of the current pulses and a target voltage.
Claims20
A method of operating a voltage regulator, comprising:
- during a finite period after the voltage regulator has been turned on, operating in a first voltage regular start mode, the finite period having a plurality of current pulses, wherein operating in the voltage regular start mode includes,
- determining a target voltage from an amount of time since the voltage regulator was turned on, wherein determining the target voltage is based on a function that monotonically increases with the amount of time since the voltage regulator was turned on, the function having a maximum value that is a reference voltage for normal operation of the voltage regulator,
- monitoring an output voltage from the voltage regulator,
- closing a switching circuit of the voltage regulator when the output voltage falls below the target voltage to commence a pulse from the plurality of current pulses,
- determining a maximum current from an ordinal of the pulse or the amount of time since the voltage regulator was turned on, wherein determining the maximum current is based on a function that monotonically increases with the ordinal of the pulse or the amount of time since the voltage regulator was turned on,
- monitoring an output current from the voltage regulator,
- opening the switching circuit when the output current exceeds the maximum current so that the output current ramps down, thereby monotonically increasing the maximum current of the current pulses and the target voltage during the finite period.
4 more elements
A controller for a voltage regulator, comprising:
- an input terminal to receive a current control signal;
- output terminals to transmit switching control signals to a switching circuit to cause the switching circuit to alternate between a first state in which an intermediate terminal is connected to an input terminal of the voltage regulator and a second state in which the intermediate terminal is connected to a ground;
- and
- control circuitry configured to, for a finite period of a start mode having a plurality of current pulses,
- determine a target voltage from an amount of time since the voltage regulator was turned on, wherein determining the target voltage is based on a function that monotonically increases with the amount of time since the voltage regulator was turned on, the function having a maximum value that is a reference voltage for a normal operation mode,
- monitor an output voltage from the voltage regulator,
- generate the switching control signals on the output terminals to cause the switching circuit to close when the output voltage falls below the target voltage to commence a pulse from the plurality of current pulses,
- determine a maximum current limit from an ordinal of the pulse or the amount of time since the voltage regulator was turned on, wherein determining the maximum current limit is based on a function that monotonically increases with the ordinal of the pulse or the amount of time since the voltage regulator was turned on,
- monitor an output current from the voltage regulator,
- generate the switching control signals to open the switching circuit when the output current exceeds the maximum current limit so that the output current ramps down, so as to monotonically increase the maximum current limit and the target voltage during the finite period of the start mode.
7 more elements
A voltage regulator having an input terminal for coupling to a voltage source and an output terminal for coupling to a load through an inductor, the voltage regulator comprising:
- a switch configured to alternately couple and decouple the voltage source through the inductor to the load;
- a feedback circuitry configured to generate a feedback current proportional to a difference between a desired voltage and an output voltage at the output terminal;
- a current sensor configured to measure the feedback current and generate a feedback current level;
- and
- a controller configured to receive the feedback current level from the current sensor and, in response thereto, to control a duty cycle of the switch, wherein the controller is configured to, for a finite period of a start mode having a plurality of current pulses,
- determine a target voltage from an amount of time since the voltage regulator was turned on, wherein determining the target voltage is based on a function that monotonically increases with the amount of time since the voltage regulator was turned on, the function having a maximum value that is a reference voltage for normal operation mode,
- monitor the output voltage from the voltage regulator,
- cause the switch to couple the load to the voltage source when the output voltage falls below the target voltage to commence a pulse from the plurality of current pulses,
- determine a maximum current limit from an ordinal of the pulse or an amount of time since the voltage regulator was turned on, wherein determining the maximum current limit is based on a function that monotonically increases with the ordinal of the pulse or the amount of time since the voltage regulator was turned on,
- monitor an output current from the voltage regulator,
- cause the switch to uncouple the load from the voltage source when the current reaches the maximum current limit so that the output current ramps down, so as to monotonically increase the maximum current limit and the target voltage during the finite period of the start mode.
8 more elements
Dependencies are inferred from the claim text.