Zero-current sensing circuit, wide input / output voltage range boost DC-DC converter and electronic devices

Abstract

A zero-current detection circuit is applied to a boost DC-DC converter, the boost DC-DC converter having an input voltage, a switching node voltage, and an output voltage, and the zero-current detection circuit having: a compensation current generation circuit for generating a compensation current based on the difference between the output voltage and the input voltage; a current multiplication circuit for generating a coefficient based on the difference between the output voltage and the switching node voltage, and generating a sensed output current based on the product of the coefficient and the compensation current; and a current comparison circuit for generating a zero-current detection voltage based on the comparison result of the sensed output current and a preset current.

Claims

1. A zero-current detection circuit applied to a boost DC-DC converter, the boost DC-DC converter having an input voltage, a switching node voltage, and an output voltage, wherein the zero-current detection circuit comprises: a compensation current generation circuit for generating a compensation current based on the difference between the output voltage and the input voltage; a current multiplication circuit for generating a coefficient based on the difference between the output voltage and the switching node voltage, and generating a sensed output current based on the product of the coefficient and the compensation current; and a current comparison circuit for generating a zero-current detection voltage based on the comparison result of the sensed output current and a preset current.

2. The zero-current detection circuit as described in claim 1, wherein, The compensation current generating circuit includes a negative feedback amplifier circuit and a current mirror circuit.

3. The zero-current detection circuit as described in claim 1, wherein, The current multiplication circuit includes a BJT current mirror circuit, having an input terminal, a first voltage sensing terminal, a second voltage sensing terminal, and an output terminal. The input terminal is used to receive the compensation current. The first voltage sensing terminal is coupled to the switching node voltage, and the second voltage sensing terminal is coupled to the output voltage. The BJT current mirror circuit generates the coefficient based on the difference between the output voltage and the switching node voltage, and generates the sensed output current based on the product of the coefficient and the compensation current. The output terminal is used to provide the sensed output current.

4. A wide input / output voltage range boost DC-DC converter, comprising an input voltage, a switching node voltage, an output voltage, and a zero-current detection circuit, wherein the zero-current detection circuit comprises: a compensation current generation circuit for generating a compensation current based on the difference between the output voltage and the input voltage; a current multiplication circuit for generating a coefficient based on the difference between the output voltage and the switching node voltage, and generating a sensed output current based on the product of the coefficient and the compensation current; and a current comparison circuit for generating a zero-current detection voltage based on the comparison result of the sensed output current and a preset current.

5. A wide input / output voltage range boost DC-DC converter as described in claim 4, wherein, The compensation current generating circuit includes a negative feedback amplifier circuit and a current mirror circuit.

6. A wide input / output voltage range boost DC-DC converter as described in request item 4, wherein, The current multiplication circuit includes a BJT current mirror circuit, having an input terminal, a first voltage sensing terminal, a second voltage sensing terminal, and an output terminal. The input terminal is used to receive the compensation current. The first voltage sensing terminal is coupled to the switching node voltage, and the second voltage sensing terminal is coupled to the output voltage. The BJT current mirror circuit generates the coefficient based on the difference between the output voltage and the switching node voltage, and generates the sensed output current based on the product of the coefficient and the compensation current. The output terminal is used to provide the sensed output current.

7. An electronic device comprising a DC-DC converter having an input voltage, a switching node voltage, an output voltage, and a zero-current detection circuit, wherein the zero-current detection circuit comprises: a compensation current generation circuit for generating a compensation current based on the difference between the output voltage and the input voltage; a current multiplication circuit for generating a coefficient based on the difference between the output voltage and the switching node voltage, and generating a sensed output current based on the product of the coefficient and the compensation current; and a current comparison circuit for generating a zero-current detection voltage based on a comparison result between the sensed output current and a preset current.

8. The electronic device as described in claim 7, wherein, The compensation current generating circuit includes a negative feedback amplifier circuit and a current mirror circuit.

9. The electronic device as claimed in claim 7, wherein, The current multiplication circuit includes a BJT current mirror circuit, having an input terminal, a first voltage sensing terminal, a second voltage sensing terminal, and an output terminal. The input terminal is used to receive the compensation current. The first voltage sensing terminal is coupled to the switching node voltage, and the second voltage sensing terminal is coupled to the output voltage. The BJT current mirror circuit generates the coefficient based on the difference between the output voltage and the switching node voltage, and generates the sensed output current based on the product of the coefficient and the compensation current. The output terminal is used to provide the sensed output current.

10. The electronic device as claimed in claim 7, which is a device selected from the group consisting of liquid crystal displays, LED displays, OLED displays and information processing devices.

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