Voltage converters with reduced output frequency variations and associated methods
AssigneeMonolithic Power Systems, Inc.
InventorsYan Dong, Peng Xu, James H. Nguyen
Life of this patent
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Abstract
Switch-mode voltage converters and associated methods are disclosed herein. In one embodiment, a switch-mode voltage converter includes a switching transistor coupled between an input voltage (Vin) and the ground and a controller coupled directly between the input voltage (Vin) and the ground. The controller is configured to periodically turn on the switching transistor for a generally constant period of time. The controller is further coupled to a DC bias voltage (Vbias) and configured to generate a control current based on the input voltage (Vin) and the DC bias voltage (Vbias) for generating a switching signal to the switching transistor.
Claims20
A switch-mode voltage converter, comprising:
- a switching transistor coupled between an input voltage (Vin) and ground;
- a controller coupled directly between the input voltage (Vin) and the ground, the controller being configured to periodically turn on the switching transistor for a generally constant period of time;
- and
- wherein the controller is further coupled to a DC bias voltage (Vbias) and configured to generate a control current based on the input voltage (Vin) and the DC bias voltage (Vbias) for generating a switching signal to the switching transistor.
A controller for controlling a switch-mode voltage converter configured to convert an input voltage (Vin) to an output voltage (Vo), the controller comprising:
- a resistor having a first end coupled to the input voltage (Vin) and a second end opposite the first end;
- a comparator having a first input terminal coupled to the second end of the resistor and a second input terminal coupled to a DC bias voltage (Vbias) of about 0.2 volt to about 5.0 volts;
- and
- a transistor having a source coupled to the resistor, a drain coupled to the ground, and a gate coupled to an output terminal of the comparator.
A method of controlling a frequency variation in an output voltage (Vo) of a switch-mode voltage converter having a switching transistor and a constant Ton controller coupled directly between the input voltage (Vin) and the ground, the constant Ton controller being configured to periodically turn on the switching transistor for a generally constant period of time, comprising:
- applying a DC bias voltage (Vbias) to the constant Tor, controller;
- varying a value of the input voltage (Vin) to the switch-mode voltage converter;
- measuring a frequency shift of the output voltage (Vo) as a result of the varied value of the input voltage (Vin);
- and
- adjusting the DC bias voltage (Vbias) based on a target value for the frequency shift.
Dependencies are inferred from the claim text.