CN-224204962-U - Switching power converter circuit

CN224204962UCN 224204962 UCN224204962 UCN 224204962UCN-224204962-U

Abstract

The utility model discloses a switching power converter circuit, which comprises a power stage circuit, a control circuit and a ramp signal generator, wherein the power stage circuit is used for generating an output voltage according to an input voltage, the control circuit is used for comparing a ramp signal with a first reference voltage to generate a control signal for controlling the power stage circuit, the ramp signal generator is coupled with the control circuit and used for generating the ramp signal and determining the slope of the ramp signal according to a plurality of reference voltages, and the reference voltages comprise the input voltage and a second reference voltage and do not comprise the output voltage.

Inventors

HUANG ZONGWEI
Cai Jieru
HUANG SHAOQI
CHEN JINGRAN

Assignees

能创半导体股份有限公司

Dates

Publication Date: 20260505
Application Date: 20250328

Claims (10)

1. A switching power converter circuit, comprising: a power stage circuit for generating an output voltage according to an input voltage; A control circuit for comparing a ramp signal with a first reference voltage to generate a control signal for controlling the power stage circuit, and The ramp signal generator is coupled to the control circuit and used for generating the ramp signal and determining the slope of the ramp signal according to a plurality of reference voltages; wherein the plurality of reference voltages includes the input voltage and a second reference voltage and does not include the output voltage.
2. The switching power converter circuit of claim 1, wherein the ramp signal generator comprises: a resistor-capacitor circuit coupled between the control circuit and the output voltage or a ground; A first current source for generating a first current, the first current being related to the input voltage, the second reference voltage and a first transduction parameter; A first switch, including a first end coupled to the first current source and a second end coupled to the control circuit, for switching on the first end to the second end according to the control signal; A second current source for generating a second current related to the second reference voltage and a second transduction parameter, and The second switch comprises a first end coupled to the second current source and a second end coupled to the control circuit for switching the conduction condition from the first end to the second end according to the control signal.
3. The switching power converter circuit of claim 2, wherein the resistor-capacitor circuit further comprises a switch for switching the connection to the output voltage or the ground.
4. The switching power converter circuit of claim 2, further comprising: The calibration circuit is coupled to the power stage circuit and the ramp signal generator, and is configured to determine one or more of the first transduction parameter, the second transduction parameter and the second reference voltage according to the output voltage and the second reference voltage, so that the output voltage approaches a target voltage.
5. The switching power converter circuit of claim 4, wherein the calibration circuit comprises: a comparison circuit for comparing the output voltage with the second reference voltage to generate a comparison result; an up-down counter coupled to the comparing circuit for generating a digital count value according to the comparing result; a digital-to-analog converter coupled to the up-down counter for generating an analog signal according to the digital count value, and The operational transconductance amplifier is coupled to the digital-to-analog converter and the ramp signal generator, and is used for generating an output current according to a voltage difference between the input voltage and the second reference voltage, and determining a conversion ratio of the voltage difference to the output current as the first conversion parameter according to the analog signal.
6. The switching power converter circuit of claim 4, wherein the calibration circuit comprises: a comparison circuit for comparing the output voltage with the second reference voltage to generate a comparison result; an up-down counter coupled to the comparing circuit for generating a digital count value according to the comparing result; a digital-to-analog converter coupled to the up-down counter for generating an analog signal according to the digital count value, and The operational transconductance amplifier is coupled to the digital-to-analog converter and the ramp signal generator, and is used for generating an output current according to a voltage difference between the second reference voltage and a ground voltage, and determining a conversion ratio of the voltage difference to the output current as the second transduction parameter according to the analog signal.
7. The switching power converter circuit of claim 4, wherein the calibration circuit comprises: a comparison circuit for comparing the output voltage with the second reference voltage to generate a comparison result; an up-down counter coupled to the comparing circuit for generating a digital count value according to the comparing result, and And a digital-to-analog converter coupled to the up-down counter for generating the second reference voltage according to the digital count value and outputting the second reference voltage to the comparison circuit.
8. The switching power converter circuit of claim 1, wherein the power stage circuit comprises: a high-side switch coupled between the input voltage and a switching node; A low-side switch coupled between the switching node and a ground terminal, and An inductor is coupled between the switching node and the output voltage.
9. The switching power converter circuit of claim 1, wherein the switching power converter circuit does not generate the ramp signal through an error amplifier.
10. The switching power converter circuit of claim 1, wherein the first reference voltage has a fixed voltage value independent of temperature.

Description

Switching power converter circuit Technical Field The present utility model relates to a switching power converter circuit, and more particularly, to a switching power converter circuit capable of improving system stability and optimizing load transient response performance. Background The switching power converter is widely applied to various electronic devices for converting an input voltage into a required output voltage. Among the many control architectures, constant On-Time (COT) control is of interest due to its simple structure and fast transient response. In particular, the switching power converter of the COT control architecture directly compares the output voltage with the reference voltage to generate the control signal, which has the advantage of having very fast load transient response performance, because the variation of the output voltage can be directly and rapidly reflected on the control signal. However, the COT control architecture lacks an appropriate frequency compensation mechanism, the closed loop stability of the system is poor, and the accuracy of the output voltage is also affected. Such instability can cause the system to oscillate under certain operating conditions, affecting the reliability of the switching power converter. This problem is particularly important in low power applications, as such applications typically require power converters with high efficiency and fast transient response, while also requiring maintenance of a stable and accurate output voltage. Therefore, it is one of the objectives in the art to ensure that the system has good closed loop stability and output voltage accuracy while maintaining a fast load transient response. Disclosure of utility model It is therefore a primary objective of the present utility model to provide a switching power converter circuit that overcomes the drawbacks of the prior art. The embodiment of the utility model provides a switching power converter circuit, which comprises a power stage circuit, a control circuit and a ramp signal generator, wherein the power stage circuit is used for generating an output voltage according to an input voltage, the control circuit is used for comparing a ramp signal with a first reference voltage to generate a control signal for controlling the power stage circuit, the ramp signal generator is coupled with the control circuit and used for generating the ramp signal and determining the slope of the ramp signal according to a plurality of reference voltages, and the reference voltages comprise the input voltage and a second reference voltage and do not comprise the output voltage. The ramp signal generator comprises a resistor-capacitor circuit coupled between the control circuit and the output voltage or a ground terminal, a first current source for generating a first current related to the input voltage, the second reference voltage and a first transduction parameter, a first switch comprising a first terminal coupled to the first current source and a second terminal coupled to the control circuit for switching the first terminal to the second terminal according to the control signal, a second current source for generating a second current related to the second reference voltage and a second transduction parameter, and a second switch comprising a first terminal coupled to the second current source and a second terminal coupled to the control circuit for switching the first terminal to the second terminal according to the control signal. The resistance-capacitance circuit further comprises a switch for switching connection with the output voltage or the ground terminal. The calibration circuit is coupled to the power stage circuit and the ramp signal generator, and is configured to determine one or more of the first transduction parameter, the second transduction parameter and the second reference voltage according to the output voltage and the second reference voltage, so that the output voltage approaches a target voltage. The calibration circuit comprises a comparison circuit for comparing the output voltage with the second reference voltage to generate a comparison result, an up-down counter coupled to the comparison circuit for generating a digital count value according to the comparison result, a digital-to-analog converter coupled to the up-down counter for generating an analog signal according to the digital count value, and an operational transconductance amplifier coupled to the digital-to-analog converter and the ramp signal generator for generating an output current according to a voltage difference between the input voltage and the second reference voltage and determining a conversion ratio of the voltage difference to the output current as the first transduction parameter according to the analog signal. The calibration circuit comprises a comparison circuit for comparing the output voltage with the second reference voltage to generate a comparison result, an up-down counter cou