Hysteretic switching regulator including a power converting unit and a switch driving unit

• US 9,595,866 B2
• Filed: 08/29/2014
• Issued: 03/14/2017
• Est. Priority Date: 12/24/2013
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Choi, Min-Ho, Keum, Dong-Jin, Yoon, Gil-Won, Ko, Yus
• Primary Examiner(s): GBLENDE, JEFFREY A
• Application Number:
  US14/472,715
• Publication Number:
  US 20150180338A1
• Time in Patent Office: 928 Days
• US Class Current: 1/1
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 3/1563 without using an external clock H02M3/158 takes precedence

Abstract

A switching regulator includes a power converting unit and a switch driving unit. The power converting unit is configured to generate a direct current (DC) output voltage based on a switch driving signal and a DC input voltage. The switch driving unit is configured to generate a ripple voltage having information of an inductor current flowing through the power converting unit, add the ripple voltage to a reference voltage to generate a first voltage having a ripple, generate a feedback voltage based on the DC output voltage, compare the first voltage with the feedback voltage in a hysteresis mode to generate a comparison output, and generate the switch driving signal based on the comparison output.

Claims

1. A switching regulator, comprising:

a power converting unit configured to generate a direct current (DC) output voltage based on a switch driving signal and a DC input voltage; and

a switch driving unit configured to generate a ripple voltage having information of an inductor current flowing through the power converting unit, add the ripple voltage to a reference voltage to generate a first voltage having a ripple, generate a feedback voltage based on the DC output voltage, compare the first voltage with the feedback voltage in a hysteresis mode to generate a comparison output, and generate the switch driving signal based on the comparison output,

wherein the power converting unit comprises;

an inductor connected between a first node to which the DC input voltage is applied and a second node;

a power switch connected to the second node, and configured to operate in response to the switch driving signal,

wherein the switch driving unit comprises;

a ripple voltage generator connected to the second node, and configured to generate the ripple voltage having the information of the inductor current flowing through the inductor,

wherein the ripple voltage generator comprises;

a resistor having a first terminal connected to the second node;

a first capacitor having a first terminal connected to a second terminal of the resistor; and

a second capacitor having a first terminal connected to the second terminal of the resistor, and a second terminal from which the ripple voltage is output.

2. The switching regulator of claim 1, wherein the switching regulator is a boost converter.

3. The switching regulator of claim 2, wherein the power converting unit comprises:

a diode connected between the second node and an output node; and

a capacitor connected between the output node and a ground voltage,

wherein the power switch is connected between the second node and the ground voltage.

4. The switching regulator of claim 3, wherein the switch driving unit comprises:

a summing circuit configured to add the ripple voltage to the reference voltage to generate the first voltage having the ripple;

a feedback circuit configured to divide the DC output voltage to generate the feedback voltage;

a comparator configured to compare the first voltage with the feedback voltage in the hysteresis mode to generate the comparison output; and

a gate driver configured to generate the switch driving signal based on the comparison output.

5. The switching regulator of claim 4, wherein the first capacitor has a second terminal to which a DC voltage is applied.

6. The switching regulator of claim 4, wherein the first capacitor has a second terminal connected to the first node.

10. The switching regulator of claim 3, wherein the switch driving unit comprises:

a summing circuit configured to add the ripple voltage to the reference voltage to generate the first voltage having the ripple;

a feedback circuit configured to divide the DC output voltage to generate a first feedback voltage and a second feedback voltage;

a first comparator configured to compare the first voltage with the first feedback voltage to generate a first comparison output;

a second comparator configured to compare the first voltage with the second feedback voltage to generate a second comparison output; and

a gate driver configured to generate the switch driving signal based on the first comparison output and the second comparison output.

11. The switching regulator of claim 10, wherein the feedback circuit comprises:

a first resistor having a first terminal connected to the output node;

a second resistor having a first terminal connected to a second terminal of the first resistor; and

a third resistor connected between a second terminal of the second resistor and the ground voltage,

wherein a first reference voltage is output from a connecting point of the first resistor and the second resistor, and a second reference voltage is output from a connecting point of the second resistor and the third resistor.

12. The switching regulator of claim 2, wherein the power converting unit comprises:

a PMOS transistor connected between the second node and an output node, and configured to operate in response to a second switch driving signal; and

a capacitor connected between the output node and a ground voltage,

wherein the power switch is connected between the second node and the ground voltage.

13. The switching regulator of claim 12, wherein the switch driving unit comprises:

a summing circuit configured to add the ripple voltage to the reference voltage to generate the first voltage having the ripple;

a feedback circuit configured to divide the DC output voltage to generate a feedback voltage;

a comparator configured to compare the first voltage with the feedback voltage in the hysteresis mode to generate the comparison output; and

a gate driver configured to generate the first switch driving signal and the second switch driving signal based on the comparison output.

7. A switching regulator, comprising:

a power converting unit configured to generate a direct current (DC) output voltage based on a switch driving signal and a DC input voltage; and

a switch driving unit configured to generate a ripple voltage having information of an inductor current flowing through the power converting unit, add the ripple voltage to a reference voltage to generate a first voltage having a ripple, generate a feedback voltage based on the DC output voltage, compare the first voltage with the feedback voltage in a hysteresis mode to generate a comparison output, and generate the switch driving signal based on the comparison output,

wherein the power converting unit comprises;

an inductor connected between a first node to which the DC input voltage is applied and a second node;

a power switch connected between the second node and a ground voltage, and configured to operate in response to the switch driving signal;

a diode connected between the second node and an output node; and

a capacitor connected between the output node and the ground voltage,

wherein the switch driving unit comprises;

a ripple voltage generator connected to the second node, and configured to generate the ripple voltage having the information of the inductor current flowing through the inductor;

a feedback circuit configured to divide the DC output voltage to generate the feedback voltage;

an amplifier configured to amplify a difference between the feedback voltage and a first reference voltage to generate a second reference voltage;

a summing circuit configured to add the ripple voltage to the second reference voltage to generate the first voltage having the ripple;

a comparator configured to compare the first voltage with the feedback voltage in the hysteresis mode to generate the comparison output; and

a gate driver configured to generate the switch driving signal based on the comparison output.

8. The switching regulator of claim 7, wherein the amplifier includes a two-input-pair differential amplifier having a first non-inverted input terminal and a second non-inverted input terminal to which the first reference voltage is applied, a first inverted input terminal to which the feedback voltage is applied, and a second inverted input terminal connected to an output terminal of the amplifier.

9. The switching regulator of claim 7, wherein the amplifier comprises:

a current source connected between a supply voltage and a third node;

a first NMOS transistor having a gate and drain commonly connected to a fourth node, and a source connected to a ground voltage;

a second NMOS transistor having a drain connected to a fifth node, a gate connected to the fourth node, and a source connected to the ground voltage;

a first PMOS transistor having a source connected to the third node, a drain connected to the fourth node, and a gate to which the first reference voltage is applied;

a second PMOS transistor having a source connected to the third node, a drain connected to the fourth node, and a gate to which the first reference voltage is applied;

a third PMOS transistor having a source connected to the third node, a drain and gate commonly connected to the fifth node; and

a fourth PMOS transistor having a source connected to the third node, a drain connected to the fifth node, and a gate to which the feedback voltage is applied, wherein the second reference voltage is output from the fifth node.

14. A switching regulator, comprising:

a first unit configured to generate a direct current (DC) output voltage in response to a switch driving signal and a DC input voltage; and

a second unit configured to control a hysteresis loop by comparing a feedback voltage and a first reference voltage indicative of an inductor current in a hysteresis mode,

wherein the switch driving signal is based on the comparison of the feedback voltage and the first reference voltage,

wherein the second unit includes a summing circuit configured to add a ripple voltage based on the inductor current and a second reference voltage to produce the first reference voltage,

wherein the ripple voltage is provided from a ripple voltage generator comprising;

a resistor having a first terminal connected to a power switch;

a first capacitor having a first terminal connected to a second terminal of the resistor, and a second terminal to which a DC voltage is applied; and

a second capacitor having a first terminal connected to the second terminal of the resistor; and

a second terminal from which the ripple voltage is output.

15. The switching regulator of claim 14, wherein the switching regulator is a boost converter or a buck converter.

16. The switching regulator of claim 14, wherein the first unit comprises:

the power switch which is connected between a first node to which the DC input voltage is applied and a second node, and configured to operate in response to the switch driving signal;

a diode connected between the second node and a ground voltage;

an inductor connected between the second node and an output node; and

a capacitor connected between the output node and the ground voltage.

17. The switching regulator of claim 16, wherein the switch driving unit comprises;

the ripple voltage generator which is connected to the second node, and configured to generate the ripple voltage having the information of the inductor current flowing through the inductor;

a feedback circuit configured to divide the DC output voltage to generate the feedback voltage;

a comparator configured to compare the first reference voltage with the feedback voltage in the hysteresis mode to generate a comparison output; and

a gate driver configured to generate the switch driving signal based on the comparison output.

18. The switching regulator of claim 14, wherein the inductor current is provided from the first unit.

19. A power converter, comprising:

a first unit configured to generate a direct current (DC) output voltage in response to a switch driving signal and a DC input voltage; and

a second unit configured to generate a ripple voltage based on an inductor current of the first unit, add the ripple voltage to a reference voltage to generate a first voltage, generate a feedback voltage based on the DC output voltage, compare the first voltage with the feedback voltage to generate a comparison output, and generate the switch driving signal based on the comparison output,

wherein the ripple voltage is provided from a ripple voltage generator comprising;

a resistor having a first terminal connected to a second node disposed between a first node to which the DC input voltage is applied and a power switch;

a first capacitor having a first terminal connected to a second terminal of the resistor, and a second terminal connected to the first node; and

a second capacitor having a first terminal connected to the second terminal of the resistor, and a second terminal from which the ripple voltage is output.