Power supply unit and calibration method to improve reliability

Patent metadata

Field	Value
Publication number	US-9923479-B2
Application number	US-201715496208-A
Country	US
Kind code	B2
Filing date	Apr 25, 2017
Priority date	Jun 3, 2016
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

A power supply includes a boost converter, a capacitor, a step-down converter and a control unit. The boost converter, when activated, converts an input voltage into a boost voltage. The capacitor has a bulk voltage which is equal to the boost voltage when the boost converter is activated. The step-down converter converts the boost voltage into a step-down voltage for output. While the boost converter is deactivated, the control unit samples the input voltage and the bulk voltage, calculates an estimated value, and determines a calibration parameter. While the boost converter is activated, the control unit calculates a calibration value for enabling the boost converter to convert the input voltage with reference to the calibration value.

First claim

What is claimed is:

1. A power supply comprising:
a boost converter configured to receive an input voltage, and to, when activated, convert the input voltage into a boost voltage;
a capacitor having a first terminal that is electrically connected to said boost converter, and a second terminal that is grounded, and further having a bulk voltage between said first terminal and said second terminal of said capacitor which is equal to the boost voltage when said boost converter is activated;
a step-down converter electrically connected to said boost converter and said first terminal of said capacitor, and configured to convert the bulk voltage into a step-down voltage for output when said boost converter is activated; and
a control unit electrically connected to said boost converter;
under a condition that said boost converter is deactivated, said control unit being programmed to sample the input voltage and the bulk voltage, to calculate, at least according to the input voltage thus sampled, an estimated value which is associated with an estimation of the bulk voltage when it is determined that the input voltage and the bulk voltage are both stable, and to determine a calibration parameter according to the estimated value and the bulk voltage thus sampled;
under a condition that said boost converter is activated, said control unit being further programmed to sample the bulk voltage, to calculate a calibration value according to the calibration parameter and the bulk voltage thus sampled, and to transmit the calibration value to said boost converter for enabling said boost converter to convert the input voltage with reference to the calibration value.

2. The power supply as claimed in claim 1 , wherein said boost converter includes:
an inductor having a first terminal that is configured to receive the input voltage, and a second terminal;
a diode having a first terminal that is electrically connected to said second terminal of said inductor, and a second terminal that is electrically connected to said first terminal of said capacitor; and
a converter switch having a first terminal that is electrically connected to said second terminal of said inductor, and a second terminal that is grounded.

3. The power supply as claimed in claim 2 , wherein under the condition that said boost converter is deactivated, said capacitor is charged via a charging path by the input voltage;
wherein said control unit is programmed to calculate the estimated value according to the equation,
V 1 =V peak −V path ,

where V 1 is the estimated value, V peak is a peak value of the input voltage, and V path is a voltage drop of the charging path, which includes said inductor and said diode.

4. The power supply as claimed in claim 3 , further comprising a resistor and a switch which is connected in parallel with said resistor, the parallel connection of said resistor and said switch being connected in series to said boost converter, V path being the voltage drop of the charging path, which further includes at least one of said resistor or said switch in addition to said inductor and said diode.

5. The power supply as claimed in claim 1 , further comprising a bypass circuit that has a first terminal configured to receive the input voltage, and a second terminal electrically connected to said first terminal of said capacitor, and that is connected in parallel with said boost converter.

6. The power supply as claimed in claim 5 , wherein under the condition that said boost converter is deactivated, said capacitor is charged via a charging path by the input voltage;
wherein said control unit is programmed to calculate the estimated value according to the equation,
V 1 =V peak −V path ,

where V 1 is the estimated value, V peak is a peak value of the input voltage, and V path is a voltage drop of the charging path, which includes said bypass circuit.

7. The power supply as claimed in claim 6 , further comprising a resistor and a switch that is connected in parallel with said resistor, the parallel connection of said resistor and said switch being connected in series to said boost converter, V path being the voltage drop of the charging path, which further includes at least one of said resistor or said switch in addition to said bypass circuit.

8. The power supply as claimed in claim 1 being configured to receive a source voltage, the power supply further comprising a rectifier, said rectifier being configured to be electrically connected to said boost converter, to receive the source voltage, and to convert the source voltage to the input voltage which is a direct current voltage.

9. The power supply as claimed in claim 8 , wherein said boost converter includes:
an inductor having a first terminal that is configured to receive the input voltage, and a second terminal;
a diode having a first terminal that is electrically connected to said second terminal of said inductor, and a second terminal that is electrically connected to said first terminal of said capacitor; and
a converter switch having a first terminal that is electrically connected to said second terminal of said inductor, and a second terminal that is grounded.

10. The power supply as claimed in claim 9 , wherein under the condition that said boost converter is deactivated, said capacitor is charged via a charging path by the input voltage;
wherein said control unit is programmed to calculate the estimated value according to the equation,
V 1 =V peak −V path ,

where V 1 is the estimated value, V peak is a peak value of the input voltage, and V path is a voltage drop of the charging path, which includes said rectifier, said inductor, and said diode.

11. The power supply as claimed in claim 10 , further comprising a resistor and a switch that is connected in parallel with said resistor, the parallel connection of said resistor and said switch being connected in series between said rectifier and said boost converter, V path being the voltage drop of the charging path, which further includes at least one of said resistor or said switch in addition to said rectifier, said inductor, and said diode.

12. The power supply as claimed in claim 8 , further comprising a bypass circuit that has a first terminal electrically connected to said rectifier, that has the first terminal configured to receive the input voltage, and a second terminal electrically connected to said first terminal of said capacitor, and that is connected in parallel with said boost converter.

13. The power supply as claimed in claim 12 , wherein under the condition that said boost converter is deactivated, said capacitor is charged via a charging path by the input voltage;
wherein said control unit is programmed to calculate the estimated value according to the equation,
V 1 =V peak −V path ,

where V 1 is the estimated value, V peak is a peak value of the input voltage, and V path is a voltage drop of the charging path, which includes said rectifier and said bypass circuit.

14. The power supply as claimed in claim 13 , further comprising a resistor and a switch that is connected in parallel with said resistor, the parallel connection of said resistor and said switch being connected in series between said rectifier and said boost converter, V path being the voltage drop of the charging path, which further includes at least one of said resistor or said switch in addition to said rectifier and said bypass circuit.

15. A calibration method for a power supply, the power supply including a boost converter, a capacitor, a

Assignees

• Lite On Electronics Guangzhou
• Lite On Tech Corp

Inventors

• Liu Yu-Shun
• Wang Shi-En
• Lo Shun-Hung

Classifications

• H02M3/156

  with automatic control of output voltage or current, e.g. switching regulators · CPC title

• H02M3/10

  using discharge tubes with control electrode or semiconductor devices with control electrode (H02M3/07 takes precedence) · CPC title

• H02M1/42

  Circuits or arrangements for compensating for or adjusting power factor in converters or inverters · CPC title

• H02M7/12 Primary

  using discharge tubes with control electrode or semiconductor devices with control electrode · CPC title

• H02M1/32

  Means for protecting converters other than automatic disconnection · CPC title