Power converter with separate buck and boost conversion circuits

1. An apparatus, comprising:

a power converter configured to convert an input voltage to an output voltage and to supply the output voltage to a load, the power converter including:

a buck conversion circuit including a first set of switches comprising first switches, and

a boost conversion circuit including a second set of switches comprising second switches, wherein the second set of switches is separate from and capable of being controlled independently from the first set of switches; and

a control unit configured to

control delivery of power from the power converter to the load via the buck conversion circuit in a buck conversion mode by controlling switching operations of the first switches using corresponding pulse width modulation (PWM) control signals, respectively, and by turning off the second set of switches, and

to control the delivery of the power from the power converter to the load via the boost conversion circuit in a boost conversion mode by controlling switching operations of the second switches using corresponding PWM control signals, respectively, and by turning off the first set of switches.

2. The apparatus of claim 1 , wherein the control unit is configured to receive a sample of the input voltage (Vinput), a sample of the output voltage, (Voutput), a sample of an input current (Iinput) supplied to the power converter, and a sample of an output current (Ioutput) supplied by the power converter, and is configured to control the delivery of the power to the load based on the sample of the input voltage, the sample of the output voltage, the sample of an input current and the sample of the output current.

3. The apparatus of claim 2 , wherein the control unit includes a plurality of analog-to-digital converter (ADCs) configured to convert the sample of the input voltage, the sample of the output voltage, the sample of the input current and the sample of the output current to digital values.

4. The apparatus of claim 2 , wherein the control unit includes circuitry configured to compare the input voltage and the output voltage to each other, wherein the control unit selects an operating mode of the power converter based on a result of the comparison.

5. The apparatus of claim 2 , wherein the control unit is configured to control the delivery of power from the power converter to the load via the buck conversion circuit by switching at least one of the first switches of the first set of switches at a switching frequency and a duty cycle of the corresponding PWM control signal, and by adjusting at least one of the switching frequency and the duty cycle in response to a difference between the sample of the input voltage and the sample of the output voltage.

6. The apparatus of claim 2 , wherein the control unit is configured to control the delivery of power from the power converter to the load via the boost conversion circuit by switching at least one of the second switches of the second set of switches at a switching frequency and a duty cycle of the corresponding PWM control signal, and by adjusting at least one of the switching frequency and the duty cycle in response to a difference between the sample of the input voltage and the sample of the output voltage.

7. The apparatus of claim 1 , wherein the control unit is configured to control delivery of power from the power converter to the load when the input voltage is greater than a sum of the output voltage and a first fixed voltage, wherein the first fixed voltage is greater than or equal to zero volts, by controlling the switching operations of the first set of switches and bypassing at least one of the turned off second switches via a first by-pass switch; and

wherein the control unit is configured to control the delivery of the power from the power converter to the load when the input voltage is less than the output voltage by controlling the switching operations of the second set of switches and bypassing at least one of the turned off first switches via a second by-pass switch.

8. The apparatus of claim 7 , wherein the first fixed voltage is less than 1 volt.

9. The apparatus of claim 7 , wherein the control unit is further configured to control the power converter to operate in a direct conversion mode when the output voltage is greater than a difference between the input voltage and the first fixed voltage, and less than a sum of the input voltage and the second fixed voltage.

10. A method, comprising:

sampling an input voltage (Vinput), an output voltage (Voutput), an input current (Iinput), and an output current (Ioutput) of a power converter that includes a buck conversion circuit including a first set of switches comprising first switches, and a boost conversion circuit including a second set of switches comprising second switches, wherein the second set of switches is separate from and capable of being controlled independently from the first set of switches;

when the input voltage is greater than a sum of the output voltage and a first fixed voltage that is greater than or equal to zero volts, controlling delivery of power from the power converter to a load by controlling switching operations of the first switches using corresponding pulse width modulation (PWM) control signals, respectively, and by turning off the second set of switches; and

when the input voltage is less than the output voltage, controlling the delivery of the power from the power converter to the load by controlling switching operations of the second switches using corresponding PWM control signal respectively, and by turning off the first set of switches.

11. The method of claim 10 , wherein controlling delivery of power from the power converter to a load further comprises bypassing at least one of the turned off second switches of the second set of switches by turning on a first by-pass switch arranged in parallel with the at least one of the turned off second switches.

12. The method of claim 11 , wherein controlling switching operations of the first switches using the corresponding PWM control signals comprises adjusting one of a frequency and a duty cycle of each PWM control signal in response to a difference between the input voltage and the output voltage.

13. The method of claim 10 , wherein controlling delivery of power from the power converter to a load further comprises bypassing at least one of the turned off first switches of the first set of switches by turning on a second by-pass switch arranged in parallel with the at least one of the turned off second switches.

14. The method of claim 13 , wherein pulse width modulating the one or more control signals comprises adjusting one of a frequency and a duty cycle of each pulse width modulated control signal in response to a difference between the input voltage and the output voltage.

15. The method of claim 10 , wherein the first fixed voltage is less than 1 volt.