Operation voltage control system and method

Abstract

This invention provides a working voltage control system and method. The working voltage control system includes a power supply circuit, at least one single-stage drive circuit, and a working voltage setting circuit. The output drive circuit is connected in series with the load between the working node and ground. The single-stage drive circuit converts the voltage margin of the output drive circuit into a digital voltage margin signal value, and sets the feedback current based on the difference between the digital voltage margin signal value and the target voltage margin value. The single-stage drive circuit draws feedback current from the working voltage setting circuit or outputs feedback current to the working voltage setting circuit. The power supply circuit outputs a working voltage to the working node, and the working voltage setting circuit adjusts the working voltage based on the set voltage and the feedback current.

Claims

1. A working voltage control system comprising: a power supply circuit configured to set a set voltage; a working voltage setting circuit connected to the power supply circuit and a working node; and a single-stage drive circuit comprising: an output drive circuit connected in series with a load between the working node and a ground terminal, configured to drive the load; an output conversion circuit connected to the output drive circuit, configured to convert a voltage margin of the output drive circuit from an analog value to a digital value as a voltage margin digital signal value; and a feedback power control circuit connected to the output conversion circuit and the working voltage setting circuit, configured to set a feedback current amount based on a voltage margin error value between the voltage margin digital signal value and a target voltage margin value, and thereby control the feedback current flowing between the working voltage setting circuit and the feedback power control circuit; wherein the power supply circuit outputs a working voltage to the working node, and the working voltage setting circuit adjusts the working voltage based on the set voltage and the feedback current.

2. The operating voltage control system as described in claim 1, wherein, When the voltage margin digital signal value is greater than the target voltage margin value, the feedback power control circuit increases the feedback current output to the working voltage setting circuit or decreases the feedback current drawn from the working voltage setting circuit; wherein, when the voltage margin digital signal value is less than the target voltage margin value, the feedback power control circuit decreases the feedback current output to the working voltage setting circuit or increases the feedback current drawn from the working voltage setting circuit; wherein, when the voltage margin digital signal value is equal to the target voltage margin value, the feedback power control circuit maintains the feedback current.

3. The operating voltage control system as claimed in claim 1, wherein the feedback power control circuit is configured to set or store a lower threshold voltage value; wherein, When the voltage margin digital signal value is less than the lower threshold voltage value, the feedback power control circuit reduces the feedback current output to the working voltage setting circuit or increases the feedback current drawn from the working voltage setting circuit; wherein, when the voltage margin digital signal value is greater than the target voltage margin value, the feedback power control circuit increases the feedback current output to the working voltage setting circuit or reduces the feedback current drawn from the working voltage setting circuit; wherein, when the voltage margin digital signal value is between the lower threshold voltage value and the target voltage margin value, the feedback power control circuit maintains the feedback current.

4. The operating voltage control system as claimed in claim 1, wherein the feedback power control circuit is configured to set or store an upper limit threshold voltage value; wherein, When the voltage margin digital signal value is greater than the upper limit threshold voltage value, the feedback power control circuit increases the feedback current output to the working voltage setting circuit or decreases the feedback current drawn from the working voltage setting circuit; wherein, when the voltage margin digital signal value is less than the target voltage margin value, the feedback power control circuit decreases the feedback current output to the working voltage setting circuit or increases the feedback current drawn from the working voltage setting circuit; wherein, when the voltage margin digital signal value is between the target voltage margin value and the upper limit threshold voltage value, the feedback power control circuit maintains the feedback current.

5. The operating voltage control system as claimed in claim 1, wherein the output drive circuit includes a drive current source, the load includes a light-emitting circuit, the positive terminal of the light-emitting circuit is connected to the operating node, the negative terminal of the light-emitting circuit is connected to a first terminal of the drive current source, and the second terminal of the drive current source is connected to the ground terminal.

6. The operating voltage control system as claimed in claim 1, wherein the output drive circuit includes a drive current source, the load includes a light-emitting circuit, a first terminal of the drive current source is connected to the operating node, a second terminal of the drive current source is connected to the positive terminal of the light-emitting circuit, and the negative terminal of the light-emitting circuit is connected to the ground terminal.

7. The operating voltage control system of claim 6, wherein the output conversion circuit comprises: a voltage margin conversion circuit connected to the output drive circuit, configured to convert the voltage difference between the operating voltage and the voltage at the output terminal of the drive current source, i.e., the voltage margin, into a voltage margin analog signal value for a pair of ground terminals; and an analog-to-digital conversion circuit connected to the voltage margin conversion circuit and the feedback power control circuit, configured to convert the voltage margin analog signal value into the voltage margin digital signal value and output it to the feedback power control circuit.

8. The operating voltage control system as claimed in claim 1, wherein the operating voltage is expressed by the following equation: VLED=X×VS+Z×IFB, where VLED represents the operating voltage, X represents a first coefficient, VS represents the set voltage, Z represents a second coefficient, IFB represents the feedback current, and the product of a unit change in Z and IFB is equal to a 1-bit resolution voltage value.

9. The operating voltage control system of claim 1, wherein the operating voltage setting circuit includes a plurality of feedback resistors connected in series between the operating node and the ground terminal; wherein the feedback power control circuit is connected to a current control node between two of the plurality of feedback resistors; wherein the power supply circuit is connected to a feedback node between two of the plurality of feedback resistors.

10. The operating voltage control system of claim 9, wherein the plurality of feedback resistors comprises: a first resistor having a first end connected to the operating node; and a second resistor having a first end connected to a second end of the first resistor and a second end connected to ground; wherein the feedback power control circuit and the power supply circuit are connected to a node between the first end of the second resistor and the second end of the first resistor.

11. The operating voltage control system of claim 10, wherein the operating voltage is expressed by the following equation: VLED = (1+R1 / R2)×VS + R1×IFB, where VLED represents the operating voltage, VS represents the set voltage, IFB represents the feedback current, R1 represents the resistance value of the first resistor, R2 represents the resistance value of the second resistor, and the product of a unit change in R1 and IFB is equal to a 1-bit resolution voltage value.

12. The operating voltage control system of claim 9, wherein the plurality of feedback resistors comprises: a first resistor having a first end connected to the operating node; a second resistor having a first end connected to a second end of the first resistor; and a third resistor having a first end connected to the second end of the second resistor and a second end connected to ground; wherein the feedback power control circuit is connected to a current control node between the first end of the second resistor and the second end of the first resistor; wherein the power supply circuit is connected to a feedback node between the first end of the third resistor and the second end of the second resistor.

13. The operating voltage control system as claimed in claim 12, wherein the operating voltage is expressed by the following equation: VLED = (1+(R1+R2) / R3)×VS + R1×IFB, where VLED represents the operating voltage, R1 represents the resistance value of the first resistor, R2 represents the resistance value of the second resistor, R3 represents the resistance value of the third resistor, VS represents the set voltage, IFB represents the feedback current, and the product of a unit change in R1 and IFB is equal to a 1-bit resolution voltage value.

14. The operating voltage control system of claim 9, wherein the plurality of feedback resistors comprises: a first resistor, a first end of the first resistor being connected to the operating node; a second resistor, a first end of the second resistor being connected to a second end of the first resistor; and a third resistor, a first end of the third resistor being connected to the second end of the second resistor, and a second end of the third resistor being connected to ground; wherein the feedback power control circuit is connected to a current control node between the first end of the third resistor and the second end of the second resistor; wherein the power supply circuit is connected to a feedback node between the first end of the second resistor and the second end of the first resistor.

15. The operating voltage control system as claimed in claim 14, wherein the operating voltage is expressed by the following equation: VLED = (1+(R1 / (R2+R3))×VS + (R1×R3 / (R2+R3))×IFB, where VLED represents the operating voltage, R1 represents the resistance value of the first resistor, R2 represents the resistance value of the second resistor, R3 represents the resistance value of the third resistor, VS represents the set voltage, IFB represents the feedback current, and the product of a unit change in (R1×R3 / (R2+R3)) and IFB is equal to a 1-bit resolution voltage value.

16. The operating voltage control system of claim 1, wherein the load comprises a plurality of load circuits, the output drive circuit comprises a plurality of sub-output drive circuits, the plurality of sub-output drive circuits are respectively connected in series with the plurality of load circuits to form a plurality of series circuits, the output conversion circuit is connected to each of the sub-output drive circuits, and the output conversion circuit is configured to convert the lowest of a plurality of voltage margins of the plurality of series circuits into a digital signal value of the voltage margin and output it to the feedback power control circuit.

17. The operating voltage control system as claimed in claim 1, wherein the feedback power control circuit is configured to set or store an upper threshold voltage value and a lower threshold voltage value; wherein, When the voltage margin digital signal value is greater than the upper threshold voltage value, the feedback power control circuit increases the feedback current output to the working voltage setting circuit or decreases the feedback current drawn from the working voltage setting circuit; wherein, when the voltage margin digital signal value is less than the lower threshold voltage value, the feedback power control circuit decreases the feedback current output to the working voltage setting circuit or increases the feedback current drawn from the working voltage setting circuit; wherein, when the voltage margin digital signal value is between the lower threshold voltage value and the upper threshold voltage value, the feedback power control circuit maintains the feedback current.

18. A working voltage control system comprising: a plurality of single-stage drive circuits sequentially connected to each other, wherein each of the single-stage drive circuits comprises: an output drive circuit connected in series with a load between a working node and a ground terminal, configured to drive the load; an output conversion circuit connected to the output drive circuit, configured to convert the voltage margin of the output drive circuit from an analog value to a digital value as a voltage margin digital signal value; and a feedback power control circuit connected to the output conversion circuit, configured to set a feedback current based on a voltage margin error value between the voltage margin digital signal value and a target voltage margin value; a power supply circuit configured to set a set voltage; and a working voltage setting circuit connected to the power supply circuit and the feedback power control circuit of the plurality of single-stage drive circuits arranged in a first stage; wherein the feedback power control circuit of the plurality of single-stage drive circuits arranged in a first stage is configured to draw the feedback current from the working voltage setting circuit or output the feedback current to the working voltage setting circuit. Each of the plurality of single-stage drive circuits has a feedback power control circuit that receives feedback current from the feedback power control circuit of the next stage; each of the plurality of single-stage drive circuits has a feedback power control circuit configured to compare its own generated feedback current with the feedback current of the next stage single-stage drive circuit and output the larger of the two; the feedback power control circuit of the first stage of the plurality of single-stage drive circuits is configured to adjust the current value of its own generated feedback current to be the same as the largest of the plurality of compared feedback currents; wherein the power supply circuit outputs an operating voltage to the operating node, and the operating voltage setting circuit adjusts the operating voltage of the power supply circuit based on the setting voltage and the feedback current received from the feedback power control circuit of the first stage of the plurality of single-stage drive circuits.

19. The operating voltage control system of claim 18, wherein the load of each of the single-stage drive circuits comprises a plurality of load circuits, the output drive circuit comprises a plurality of sub-output drive circuits, the plurality of sub-output drive circuits are respectively connected in series with the plurality of load circuits, the output conversion circuit is connected to each of the sub-output drive circuits, and the output conversion circuit selects the lowest of a plurality of voltage margins and converts it into a digital signal value of the voltage margin, which is then output to the feedback power control circuit.

20. A method for controlling operating voltage, comprising: driving a load using an output drive circuit; configuring an output conversion circuit to convert the voltage margin of the output drive circuit into a digital value as a voltage margin digital signal value; configuring a feedback power control circuit to set a feedback current based on a voltage margin error value between the voltage margin digital signal value and a target voltage margin value; configuring a power supply circuit to set a set voltage; using the feedback power control circuit to output the feedback current to an operating voltage setting circuit, or to draw the feedback current from the operating voltage setting circuit; and using the operating voltage setting circuit to adjust an operating voltage based on the set voltage and the feedback current, and outputting the adjusted operating voltage to the load or the output drive circuit, wherein the operating voltage is expressed by the following equation: VLED = X × VS + Z × IFB. Where VLED represents the operating voltage, X represents a first coefficient, VS represents the set voltage, Z represents a second coefficient, IFB represents the feedback current, and the product of the unit change of Z and IFB is equal to a 1-bit resolution voltage value.

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