Power supply circuit and control method thereof
AssigneeRichtek Technology Corporation
InventorsJing-Meng Liu, Hung-Der Su
Life of this patent
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Abstract
A power supply circuit and a control method are provided, in which the original enable pad and output pad, or the enable pad and feedback pad are used to trim the output voltage of the power supply circuit without extra trim pads.
Claims38
A power supply circuit, comprising:
- an output pad;
- an enable pad for enabling said power supply circuit by receiving an enable signal in a normal mode;
- a trim circuit;
- and
- a voltage regulator for providing an output voltage to said output pad in said normal mode and providing a first voltage proportional to said output voltage for said trim circuit in a test mode;
- wherein in said test mode, said enable pad receives a test signal to signal said trim circuit to perform a trim function, a second voltage is coupled to said output pad, and said trim circuit trims said output voltage in response to said first and second voltages.
A power supply circuit, comprising:
- an output pad;
- an enable pad for enabling said power supply circuit by receiving an enable signal in a normal mode;
- a trim circuit;
- a voltage regulator for providing an output voltage to said output pad in said normal mode and providing a first voltage proportional to said output voltage for said trim circuit in a test mode;
- and
- a feedback pad for feeding back said output voltage to said power supply circuit;
- wherein in said test mode, said enable pad receives a test signal to signal said trim circuit to perform a trim function, a second voltage is coupled to said output pad, and said trim circuit trims said output voltage in response to said first and second voltages.
A control method for a power supply circuit, said power supply circuit including an output pad, an enable pad, a trim circuit, and a voltage regulator, said trim circuit having a variable resistor coupled to said voltage regulator, said voltage regulator providing an output voltage to said output pad in a normal mode and providing a first voltage proportional to said output voltage for said trim circuit in a test mode, said control method comprising the steps of receiving a test signal and a second voltage by said enable pad and said output pad, respectively, and trimming said output voltage by said test signal and said first and second voltages in said test mode.
A control method for a power supply circuit, said power supply circuit including an output pad, an enable pad, a feedback pad, a trim circuit, and a voltage regulator, said trim circuit having a variable resistor coupled to said voltage regulator, in a normal mode, said voltage regulator providing an output voltage to said output pad, and said output voltage fed back to said power supply circuit by said feedback pad, in a test mode, said voltage regulator providing a first voltage proportional to said output voltage for said trim circuit, said control method comprising the steps of receiving a test signal and a second voltage by said enable pad and said output pad, respectively, and trimming said output voltage by said test signal and said first and second voltages in said test mode.
Dependencies are inferred from the claim text.