Switching controller circuit

• US 10,027,219 B1
• Filed: 09/13/2017
• Issued: 07/17/2018
• Est. Priority Date: 08/09/2017
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Inventors: Ye, Wanfu, Wang, Lingling
• Primary Examiner(s): Tran, Nguyen
• Assistant Examiner(s): Dang, Trinh Q
• Application Number:
  US15/702,767
• Time in Patent Office: 307 Days
• CPC Class Codes: G05F 1/46 wherein the variable actually regulated by the final control device is dc G05F1/625 takes precedence
• CPC Class Codes: H02M 1/00 Details of apparatus for conversion
• CPC Class Codes: H02M 1/0006 Arrangements for supplying an adequate voltage to the control circuit of converters
• CPC Class Codes: H02M 1/0025 Arrangements for modifying reference values, feedback values or error values in the control loop of a converter
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• CPC Class Codes: H02M 1/08 Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 3/157 with digital control
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A switching controller circuit for a power converter includes analog and digital control circuits, a clock enable circuit, and a digital pulse width modulation (PWM) circuit. When the power converter is in a standby mode, the switching controller circuit operates in an analog control mode by activating the analog control circuit. When the power converter is not in standby mode, the switching controller circuit activates the digital control circuit and operates in a digital control mode. The switching controller circuit uses inexpensive electronic components and consumes less power in the analog control mode, thereby reducing standby mode power consumption.

Claims

1. A switching controller circuit that is operable in at least one of first and second control modes, comprising:

an analog control circuit that generates a pulse control signal in the first control mode, wherein the analog control circuit includes;

a peak-valley detector that receives an analog clock gate enable signal and generates the pulse control signal;

a comparator circuit that receives a reference signal, a load voltage signal, a clock signal, and the analog clock gate enable signal, and is connected to the peak-valley detector for receiving the pulse control signal, and that generates a comparator interrupt signal; and

a timer circuit that receives the analog clock gate enable signal, and is connected to the peak-valley detector for receiving the pulse control signal, and that generates a timer interrupt signal based on a predetermined count value;

a digital control circuit that generates a digital control signal in the second control mode, wherein the digital control circuit includes;

an analog-to-digital converter (ADC) circuit that receives the load voltage signal, the clock signal, and a digital clock gate enable signal and outputs a digitized load voltage signal; and

a processing circuit that receives a processing clock gate enable signal and the clock signal, and is connected to the ADC circuit for receiving the digitized load voltage signal, the timer circuit for receiving the timer interrupt signal, and the comparator circuit for receiving the comparator interrupt signal, wherein the processing circuit outputs control mode data and the digital control signal;

a clock enable circuit connected to the comparator circuit, the timer circuit, and the processing circuit for receiving the comparator interrupt signal, the timer interrupt signal, and the control mode data, respectively, wherein the clock enable circuit generates the analog clock gate enable signal, the digital clock gate enable signal, and the processing clock gate enable signal, wherein;

the switching controller circuit operates in the first control mode when the analog clock gate enable signal is active, and the digital clock gate enable signal and the processing clock gate enable signal are not active; and

the switching controller circuit operates in the second control mode when the analog clock gate enable signal is not active, and the digital clock gate enable signal and the processing clock gate enable signal are active; and

a digital pulse width modulation (PWM) circuit connected to the analog and digital control circuits, wherein the digital PWM circuit receives the pulse control signal from the analog control circuit when the clock enable circuit outputs the analog clock gate enable signal, the digital control signal from the digital control circuit when the clock enable circuit outputs the digital clock gate enable signal, and outputs a pulse wave signal corresponding to at least one of the pulse control signal and the digital control signal.

2. The switching controller circuit of claim 1, wherein the peak-valley detector includes:

a level comparator circuit that generates first and second comparison signals based on the load voltage signal and the analog clock gate enable signal; and

an AND-OR-Invert (AOI) circuit, connected to the level comparator circuit for receiving the first and second comparison signals, and generating the pulse control signal.

3. The switching controller circuit of claim 1, wherein the comparator circuit includes:

a comparator that receives the load voltage signal and the reference signal, and generates a load output under-voltage signal;

a window circuit, connected to the peak-valley detector and the comparator for receiving the pulse control signal and the load output under-voltage signal, respectively, that outputs a windowed load output under-voltage signal;

a filter circuit connected to the window circuit for receiving the windowed load output under-voltage signal, and generating a filtered load output under-voltage signal; and

a multiplexer, connected to the window circuit and the filter circuit for receiving the windowed load output under-voltage signal and the filtered load output under-voltage signal, respectively, that outputs the comparator interrupt signal based on a filter enable signal.

4. The switching controller circuit of claim 1, wherein the timer circuit includes:

a counter that generates a count signal based on the clock signal, the pulse control signal, and the reset signal;

a capture circuit, connected to the peak-valley detector for receiving the pulse control signal, that generates the reset signal; and

a compare circuit, connected to the counter that receives the count signal, that generates the timer interrupt signal.

5. The switching controller circuit of claim 1, wherein when the pulse control signal is active, the digital PWM circuit generates the pulse wave signal with a constant pulse width and a constant frequency, and when the pulse control signal is not active, the digital PWM circuit outputs the pulse wave signal as a ground signal.

6. The switching controller circuit of claim 1, wherein the pulse wave signal generated by the PWM circuit has a pulse width and a frequency corresponding to the digital control signal.

7. The switching controller circuit of claim 1, wherein:

the processing circuit and the ADC circuit receive the clock signal when the digital clock gate enable signal and the processing clock gate enable signal are active; and

the comparator circuit, the level comparator circuit and the timer circuit receive the clock signal when the analog clock gate enable signal is active.

8. The switching controller circuit of claim 1, wherein the first control mode is an analog control mode, and the second control mode is a digital control mode.

9. The switching controller circuit of claim 2, wherein the level comparator circuit includes:

a first comparator that receives an upper-limit voltage signal and the load voltage signal, and generates a first comparison signal; and

a second comparator that receives a lower-limit voltage signal and the load voltage signal, and generates a second comparison signal.

10. The switching controller circuit of claim 9, wherein the AOI circuit includes:

a first logic gate that receives the pulse control signal, and the first comparison signal, and generates an error hold signal;

a second logic gate that receives an inverted pulse control signal and the second comparison signal, and generates a loss hold signal; and

a third logic gate, connected to the first and second logic gates for receiving the error hold signal and the loss hold signal, respectively, that outputs the pulse control signal.

11. The switching controller circuit of claim 10, wherein the first and second logic gates are AND gates, and the third logic gate is an OR gate.

12. A switching controller circuit for a power converter that is operable in at least one of first and second control modes, the switching controller comprising:

an analog control circuit that generates a pulse control signal in the first control mode, wherein the analog control circuit includes;

a peak-valley detector that generates the pulse control signal based on an analog clock gate enable signal;

a comparator circuit, connected to the peak-valley detector for receiving the pulse control signal, that generates a comparator interrupt signal based on the analog clock gate enable signal, wherein the comparator circuit includes;

a comparator that receives a load voltage signal and a reference signal, and outputs a load output under-voltage signal;

a window circuit, connected to the peak-valley detector and the comparator for receiving the pulse control signal and the load output under-voltage signal, respectively, that generates a windowed load output under-voltage signal;

a filter circuit, connected to the window circuit for receiving the windowed load output under-voltage signal, that outputs a filtered load output under-voltage signal; and

a multiplexer, connected to the window circuit and the filter circuit for receiving the windowed load output under-voltage signal and the filtered load output under-voltage signal, respectively, that outputs the comparator interrupt signal based on a filter enable signal; and

a timer circuit, connected to the peak-valley detector for receiving the pulse control signal, that generates a timer interrupt signal based on the analog clock gate enable signal, wherein the timer circuit includes;

a counter that generates a count signal based on a clock signal, the pulse control signal, and a reset signal;

a capture circuit connected to the peak-valley detector for receiving the pulse control signal and generating the reset signal; and

a compare circuit, connected to the counter that receives the count signal, that generates the timer interrupt signal based on a predetermined count value;

a digital control circuit that generates a digital control signal in the second control mode, wherein the digital control circuit includes;

an analog-to-digital converter (ADC) circuit that receives the load voltage signal and outputs a digitized load voltage signal based on a digital clock gate enable signal; and

a processing circuit connected to the ADC circuit for receiving the digitized load voltage signal, the timer circuit for receiving the timer interrupt signal, and the comparator circuit for receiving the comparator interrupt signal, wherein the processing circuit generates control mode data and the digital control signal based on a processing clock gate enable signal;

a clock enable circuit connected to the comparator circuit, the timer circuit, and the processing circuit for receiving the comparator interrupt signal, the timer interrupt signal, and the control mode data, respectively, wherein the clock enable circuit generates the analog clock gate enable signal, the digital clock gate enable signal, and the processing clock gate enable signal, wherein;

the switching controller circuit operates in the first control mode when the analog clock gate enable signal is active, and the digital clock gate enable signal and the processing clock gate enable signal are not active,

the switching controller circuit operates in the second control mode when the analog clock gate enable signal is not active, and the digital clock gate enable signal and the processing clock gate enable signal are active; and

a digital pulse width modulation (PWM) circuit connected to the analog and digital control circuits, wherein the digital PWM circuit receives;

(i) the pulse control signal from the analog control circuit when the analog clock gate enable signal is active, (ii) the digital control signal from the digital control circuit when the digital clock gate enable signal is active, and (iii) outputs a pulse wave signal corresponding to one of the pulse control signal and the digital control signal.

13. The switching controller circuit of claim 12, wherein the peak-valley detector includes:

a level comparator circuit that receives the load voltage signal, the upper-limit voltage signal, the lower-limit voltage signal, the clock signal, and the analog clock gate enable signal, and outputs first and second comparison signals; and

an AND-OR-Invert (AOI) circuit, connected to the level comparator circuit, that generates the pulse control signal from the first and second comparison signals.

14. The switching controller circuit of claim 12, wherein when the pulse control signal is active, the digital PWM circuit outputs the pulse wave signal having a constant pulse width and a constant frequency, and when the pulse control signal is not active, the pulse wave signal is a ground signal.

15. The switching controller circuit of claim 12, wherein the pulse wave signal generated by the digital PWM circuit has a pulse width and a frequency corresponding to the digital control signal.

16. The switching controller circuit of claim 12, wherein:

the processing circuit and the ADC circuit receive the clock signal when the digital clock gate enable signal and the processing clock gate enable signal are active; and

the comparator circuit, the level comparator circuit and the timer circuit receive the clock signal when the analog clock gate enable signal is active.

17. The switching controller circuit of claim 12, wherein the first control mode is an analog control mode, and the second control mode is a digital control mode.

18. The switching controller circuit of claim 13, wherein the level comparator circuit includes:

a first comparator that receives the upper-limit voltage signal and the load voltage signal, and generates a first control signal; and

a second comparator that receives the lower-limit voltage signal and the load voltage signal, and generates a second control signal.

19. The switching controller circuit of claim 18, wherein the AOI circuit includes:

a first logic gate that receives the pulse control signal, and is connected to the first comparator for receiving the first comparison signal, and generates an error hold signal;

a second logic gate that receives an inverted pulse control signal, and is connected to the second comparator for receiving the second comparison signal, and generates a loss hold signal; and

a third logic gate connected to the first and second logic gates for receiving the error hold signal and the loss hold signal, respectively, and generates the pulse control signal.

20. The switching controller circuit of claim 19, wherein the first and second logic gates are AND gates, and the third logic gate is an OR gate.