Power supply with DC breaker switch and reduced regulated DC link voltage
Generally, this disclosure provides circuits and methods to reduce and regulate DC link voltage in a power supply through the use of a DC breaker circuit. The breaker circuit may include a breaker switch configured to couple an input stage circuit of a power supply to an output stage circuit of the power supply and to provide a regulated DC link voltage to the output stage circuit, the level of the DC link voltage based on switching states of the breaker switch. The breaker circuit may further include a control circuit configured to generate a gate control signal to control the switching states of the breaker switch, the gate control signal based on a comparison of the DC link voltage to a high voltage threshold and a low voltage threshold, such that the magnitude of the DC link voltage is regulated to a set point and a peak-to-peak ripple.
1. A direct current (DC) breaker circuit comprising:
a breaker switch configured to couple an input stage circuit of a power supply to an output stage circuit of said power supply and to provide a regulated DC link voltage to said output stage circuit, the level of said DC link voltage based on switching states of said breaker switch;
a control circuit configured to generate a gate control signal to control said switching states of said breaker switch, said gate control signal based on a comparison of said DC link voltage to a high voltage threshold and a low voltage threshold, such that the magnitude of said DC link voltage is regulated to a set point and a peak-to-peak ripple; and
said control circuit further configured to generate said gate control signal such that said breaker switch state changes are synchronized with a frequency of a voltage provided by said input stage circuit to provide a zero voltage switching (ZVS) condition of said breaker switch.
2. The DC breaker circuit of claim 1 , further comprising a hysteresis control circuit configured to limit switching state changes of said breaker circuit in response to noise associated with said voltage provided by said input stage circuit.
3. The DC breaker circuit of claim 1 , wherein said breaker switch is a synchronous bridge rectifier.
4. The DC breaker circuit of claim 1 , wherein said breaker switch is a bridgeless rectifier.
5. A method for reducing and regulating a DC link voltage in a power supply, said method comprising:
coupling an input stage circuit of a power supply to an output stage circuit of said power supply with a breaker switch;
configuring said breaker switch to provide a DC link voltage to said output stage circuit, the level of said DC link voltage based on switching states of said breaker switch;
generating a gate control signal to control said switching states of said breaker switch, said gate control signal based on a comparison of said DC link voltage to a high voltage threshold and a low voltage threshold, such that the magnitude of said DC link voltage is regulated to a set point and a peak-to-peak ripple; and
timing said gate control signal such that said breaker switch state changes provide a zero voltage switching (ZVS) condition of said breaker switch.
6. The method of claim 5 , wherein said breaker switch is a bridgeless rectifier.
7. The method of claim 5 , wherein said breaker switch is a synchronous bridge rectifier.
8. The method of claim 5 , further comprising limiting switching state changes of said breaker switch in response to noise associated with said voltage provided by said input stage circuit.
9. A power supply system comprising:
an input stage circuit configured to accept an input voltage;
an output stage circuit configured to provide an output voltage;
a breaker switch configured to couple said input stage circuit to said output stage circuit and to provide a regulated DC link voltage to said output stage circuit, the level of said DC link voltage based on switching states of said breaker switch; and
a control circuit configured to generate a gate control signal to control said switching states of said breaker switch, said gate control signal based on a comparison of said DC link voltage to a high voltage threshold and a low voltage threshold, such that the magnitude of said DC link voltage is regulated to a set point and a peak-to-peak ripple.
10. The power supply system of claim 9 , wherein said power supply is a switched mode power supply and said input stage circuit comprises an electromagnetic interference (EMI) filter.
11. The power supply system of claim 9 , wherein said breaker switch is a bridgeless rectifier.
12. The power supply system of claim 9 , wherein said breaker switch is a synchronous bridge rectifier.
13. The power supply system of claim 9 , further comprising a hysteresis control circuit configured to limit switching state changes of said breaker switch in response to noise associated with said voltage provided by said input stage circuit.
14. The power supply system of claim 9 , wherein said control circuit is further configured to generate said gate control signal such that said breaker switch state changes are synchronized with a frequency of a voltage provided by said input stage circuit to provide a zero voltage switching (ZVS) condition of said breaker switch.