Conversion control circuit and method for use in stackable multiphase power converter

1 . A conversion control circuit for controlling a stackable sub-converter, wherein a plurality of stackable sub-converters are configured as a stackable multi-phase power converter, wherein each of the plurality of stackable sub-converters includes a power stage circuit and a corresponding conversion control circuit, wherein a plurality of power stage circuits corresponding to the plurality of stackable sub-converters are coupled in parallel to generate an output power to a load, the output power including an output current, wherein the conversion control circuit is configured to control at least one switch of the power stage circuit to switch an inductor corresponding to the power stage circuit, thereby generating the output power, wherein the conversion control circuit is configured as a master control circuit or a slave control circuit, wherein the plurality of stackable sub-converters have a total phase number and an activated phase number, wherein the activated phase number is determined according to a level of the output current, wherein the conversion control circuit comprises:

a current sharing terminal, wherein a current sharing signal is coupled to current sharing terminals of plural conversion control circuits that are coupled in parallel;

a current sharing circuit, configured to generate and/or receive the current sharing signal, and to generate an adjustment signal according to a difference between the current sharing signal and a sub-current sensing signal to adjust at least one parameter of the conversion control circuit for current sharing between the plurality of stackable sub-converters, wherein the sub-current sensing signal is related to an inductor current corresponding to the inductor;

wherein the current sharing circuit includes the following configurations:

(A): wherein the current sharing signal is generated only according to the inductor current corresponding to one of the plurality of stackable sub-converters, wherein the current sharing circuit of the master control circuit does not generate the adjustment signal and does not adjust the at least one parameter of the conversion control circuit, wherein the current sharing circuit of each of the plural slave control circuits generates the adjustment signal to adjust the at least one parameter for current sharing between the plurality of stackable sub-converters; or

(B): wherein the current sharing signal is generated according to the inductor currents of the inductors of plural activated phases of the plurality of stackable sub-converters, wherein a ratio of a portion of the current sharing signal generated by the master control circuit to a portion generated by each activated one of plural slave control circuits is k which relates to a difference between the total phase number and the activated phase number.

2 . The conversion control circuit as claimed in claim 1 , wherein in configuration (A), the current sharing signal is generated only according to the inductor current corresponding to the master control circuit.

3 . The conversion control circuit as claimed in claim 2 , wherein the conversion control circuit further comprises:

a sync terminal, wherein a sync signal is coupled to plural sync terminals of the plural conversion control circuits that are coupled in parallel;

wherein the sync signal includes plural pulses, the plural pulses are continuously counted as a counting value, wherein the sync signal includes a reset signal for resetting and initiating the counting value;

wherein when the counting value is related to a phase sequence number corresponding to the conversion control circuit, the conversion control circuit enables a corresponding one of the plurality of power stage circuits to generate the output power;

wherein the master control circuit is configured to generate the sync signal via the sync terminal, and the slave control circuit is configured to receive the sync signal via the sync terminal.

4 . The conversion control circuit as claimed in claim 3 , wherein when the counting value reaches the activated phase number, the reset signal is generated, wherein one pulse of the sync signal with a higher voltage level is indicative of the reset signal.

5 . The conversion control circuit as claimed in claim 3 , wherein the stackable sub-converter is activated by triggering of a corresponding pulse of the sync signal.

6 . The conversion control circuit as claimed in claim 3 , wherein the conversion control circuit is configured as an integrated circuit, wherein the sync terminal corresponds to a sync pin of the integrated circuit, and the current sharing terminal corresponds to a current sharing pin of the integrated circuit.

7 . The conversion control circuit as claimed in claim 1 , wherein in the configuration (B), the current sharing circuit of each of the master control circuit and the slave control circuit generates the adjustment signal to correspondingly adjust the at least one parameter, for current sharing between the plurality of stackable sub-converters.

8 . The conversion control circuit as claimed in claim 1 , wherein the conversion control circuit controls at least one switch of one of the plurality of stackable sub-converters using a constant time, wherein the constant time is determined according to a threshold voltage, an integral capacitance value, or an integral current; wherein the adjustment signal is configured to adjust the at least one parameter to modify the constant time for current sharing between the plurality of stackable sub-converters, wherein the at least one parameter includes at least one of the threshold voltage, the integral capacitance value, and the integral current.

9 . The conversion control circuit as claimed in claim 8 , further comprising a transconductance circuit and a filtering circuit, wherein the transconductance circuit is configured to generate a transconductance current according to the difference between the current sharing signal and the sub-current sensing signal, and the filtering circuit is configured to generate an amplified output signal according to the transconductance current, wherein the adjustment signal corresponds to the amplified output signal, and the amplified output signal corresponds to the threshold voltage.

10 . A control method, for controlling a stackable sub-converter, wherein a plurality of stackable sub-converters are configured as a stackable multi-phase power converter, wherein each of the plurality of stackable sub-converters includes a power stage circuit, wherein a plurality of power stage circuits corresponding to the plurality of stackable sub-converters are coupled in parallel to generate an output power to a load, wherein the power stage circuit includes at least one switch for switching an inductor corresponding to the power stage circuit, thereby generating the output power, wherein one of the plurality of stackable sub-converters is configured as a master stackable sub-converter, and each of others of the plurality of stackable sub-converters is configured as a slave stackable sub-converter, wherein the plurality of stackable sub-converters have a total phase number and an activated phase number, wherein the control method comprises:

controlling the at least one switch of the power stage circuit for switching the inductor;

generating or receiving a current sharing signal by each of the plurality of stackable sub-converters; and

performing current sharing between the plurality of stackable sub-converters according to the current sharing signal according to a difference between the current sharing signal and a sub-current sensing signal, wherein the sub-current sensing signal is related to an inductor current corresponding to the inductor;

wherein the step of generating the current sharing signal includes the following configurations:

(A): generating the current sharing signal only according to the inductor current corresponding to one of the plurality of stackable sub-converters, wherein the power stage circuit of the master stackable sub-converter is not adjusted, wherein a corresponding one of the plurality of power stage circuits of each of slave stackable sub-converters is adjusted to adjust corresponding at least one parameter for current sharing between the plurality of stackable sub-converters; or

(B): generating the current sharing signal according to the inductor currents of the inductors of plural activated phases of the plurality of stackable sub-converters, wherein a ratio of a portion of the current sharing signal generated by the master stackable sub-converter to a portion generated by each activated one of the slave stackable sub-converter or the slave stackable sub-converters is k which relates to a difference between the total phase number and the activated phase number.

11 . The control method as claimed in claim 10 , wherein in the configuration (A), the current sharing signal is generated only according to the corresponding inductor current corresponding to the master stackable sub-converter.

12 . The control method as claimed in claim 11 , further comprising:

generating a sync signal by the master stackable sub-converter;

receiving the sync signal by the slave stackable sub-converter, wherein the sync signal includes plural pulses, the plural pulses are continuously counted as a counting value, wherein the sync signal includes a reset signal for resetting and initiating the counting value; and

enabling a corresponding power stage circuit to generate the output power when the counting value is related to a corresponding phase sequence number.

13 . The control method as claimed in claim 12 , further comprising:

indicating the reset signal by one pulse of the sync signal with a higher voltage level; and

generating the reset signal when the counting value reaches the activated phase number.

14 . The control method as claimed in claim 12 , further comprising: activating the stackable sub-converter by triggering of a corresponding pulse of the sync signal.

15 . The control method as claimed in claim 10 , wherein in the configuration (B), generating a corresponding adjustment signal for each of the master stackable sub-converter and the slave stackable sub-converter to correspondingly adjust at least one parameter, for current sharing between the plurality of stackable sub-converters.

16 . The control method as claimed in claim 10 , further comprising:

controlling the at least one switch of one of the plurality of stackable sub-converters using a constant time, wherein the constant time is determined according to a threshold voltage, an integral capacitance value, or an integral current; and

adjusting at least one parameter to modify the constant time for current sharing between the plurality of stackable sub-converters, wherein the at least one parameter includes at least one of the threshold voltage, the integral capacitance value, and the integral current.

17 . The control method as claimed in claim 16 , further comprising:

generating a transconductance current according to the difference between the current sharing signal and the sub-current sensing signal; and

generating an amplified output signal according to the transconductance current, wherein the amplified output signal corresponds to the threshold voltage.