SWITCHING REGULATION CONTROLLER, SWITCHING REGULATOR AND CONTROLLING METHOD FOR SWITCHING REGULATION

• US 20110267016A1
• Filed: 04/27/2011
• Published: 11/03/2011
• Est. Priority Date: 04/28/2010
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: KAJIYAMA, Shinya
• Granted Patent: US 8,823,349 B2
• Time in Patent Office: Days
• US Class Current: 323/271
• CPC Class Codes: H02M 3/157 with digital control

Abstract

A switching regulation controller for driving a switch circuit included in a switching regulator which converts an input voltage to a target voltage, and outputs the target voltage. The switching regulation controller detects an error between the output voltage and the target voltage, and uses the detected error and a control amount generated before to generate a control amount for controlling the switch circuit so that the output voltage is coincident with the target voltage according to a given transfer function. When the detected error reaches below a given value, the switching regulation controller generates the control amount using a candidate value smaller than the control amount instead of the control amount generated before. With switching regulation controller, the switching regulator, and the controlling method for switching generation, the overshoot at the rise of an output voltage is reduced without sacrificing the rising time of the output voltage.

Claims

1. A switching regulation controller for driving a switch circuit included in a switching regulator which converts a voltage input thereto into a target voltage, and outputs the target voltage, comprising:

an error detection unit which samples the output voltage, and generates and outputs error data showing an error between the sampled output voltage and the target voltage;

a control-amount-generating unit which uses the error data, error data generated before, and a control amount generated before to generate a control amount for controlling the switch circuit so that the output voltage is coincident with the target voltage according to a given transfer function; and

a driving-signal-generating unit which generates a signal having a pulse width depending on the control amount, and outputs the generated signal as a driving signal for driving the switch circuit,

wherein on condition that an error value shown by the error data is smaller than a given value, the control-amount-generating unit conducts one of the steps of;

generating the control amount using a candidate value smaller than the control amount instead of the control amount generated before; and

generating the control amount using a candidate value smaller than the error data instead of the error data corresponding to the control amount generated before.

2. The switching regulation controller according to claim 1,

wherein the control-amount-generating unit performs the step of generating the control amount using the candidate value only once.

3. The switching regulation controller according to claim 1,

wherein the control-amount-generating unit has:

a first storing unit which stores a given threshold value;

a comparing unit which compares a value of the first storing unit with a value of error involved in the error data, and outputs a result of the comparison;

a calculating unit which uses the error data and the control amount generated before to calculate a new control amount according to the given transfer function; and

a second storing unit which stores one of a candidate value smaller than the control amount and a candidate value smaller than the error data, and

wherein, on condition that the comparison result output by the comparing unit shows a value of error involved in the error data is smaller than the threshold, the calculating unit performs one of the steps of;

executing the calculation using, instead of the control amount generated before, the candidate value smaller than the control amount, which is put in the second storing unit; and

executing the calculation using, instead of the error data corresponding to the control amount generated before, the candidate value smaller than the error data, which is put in the second storing unit.

4. The switching regulation controller according to claim 3,

wherein the first and second storing units are both externally rewritable.

5. The switching regulation controller according to claim 1,

wherein the control-amount-generating unit is composed of a processor for digital signal processing.

6. The switching regulation controller according to claim 1,

wherein the switching regulation controller is formed on a semiconductor substrate.

7. A switching regulator which conducts a conversion from an input voltage to a target voltage and outputs the target voltage, comprising:

a switch circuit in charge of the conversion;

an error detection unit which samples the output voltage, and generates and outputs error data showing an error between the sampled output voltage and the target voltage;

a control-amount-generating unit which uses the error data, error data generated before, and a control amount generated before to generate a control amount for controlling the switch circuit so that the output voltage is coincident with the target voltage according to a given transfer function; and

a driving-signal-generating unit which generates a signal having a pulse width depending on the control amount, and outputs the generated signal as a driving signal for driving the switch circuit,

wherein, on condition that an error value shown by the error data is smaller than a given value, the control-amount-generating unit conducts one of the steps of;

generating the control amount using a candidate value smaller than the control amount instead of the control amount generated before; and

generating the control amount using a candidate value smaller than the error data instead of the error data corresponding to the control amount generated before.

8. A controlling method for switching regulation for controlling a switch circuit included in a switching regulator thereby to output a target voltage, comprising:

a first step of sampling the output voltage, and then detecting an error between the sampled output voltage and the target voltage;

a second step of detecting a given condition in which the error becomes smaller than a given threshold;

a third step of using a control amount generated before and a value of the error to generate a control amount for controlling the switch circuit so that the output voltage is coincident with the target voltage, according to a given transfer function on condition that the given condition is not detected;

a fourth step of using a candidate value smaller than the control amount generated before and the error value to generate the control amount according to the given transfer function on detection of the given condition; and

a fifth step of generating a signal having a pulse width depending on the generated control amount, and driving the switch circuit.

9. The controlling method for switching regulation according to claim 8,

wherein the given condition is a condition where the error first becomes smaller than the given threshold.