ELECTRONIC CONTROLLER WITH AUTOMATIC ADJUSTMENT TO UNKNOWN INPUT AND LOAD VOLTAGES

• US 20170104411A1
• Filed: 10/09/2015
• Published: 04/13/2017
• Est. Priority Date: 10/09/2015
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Tomasovics, Attila, Mohamed Saat, Muhammad Nur Syafii
• Granted Patent: US 9,954,438 B2
• Time in Patent Office: Days
• CPC Class Codes: H02M 1/44 Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
• CPC Class Codes: H02M 3/157 with digital control
• CPC Class Codes: H02M 3/33507 with automatic control of the output voltage or current, e.g. flyback converters H02M3/33561, H02M3/33569 take precedence

Abstract

Methods, devices, techniques, and circuits are disclosed for current control of a buck converter. In one example, a device is configured to receive a selected average current value for a current driver. The device is further configured to determine a set of parameters for the current driver. The device is further configured to generate an output to the current driver to cause the current driver to output a switching signal with an average current that corresponds to the selected average current value.

Claims

1. A device configured to:

receive a selected average current value for a current driver;

determine a set of parameters for the current driver; and

generate an output to the current driver to cause the current driver to output a switching signal with an average current that corresponds to the selected average current value.

2. The device of claim 1, wherein determining the set of parameters for the current driver comprises measuring an input voltage.

3. The device of claim 1, wherein determining the set of parameters for the current driver comprises measuring an inductor voltage.

4. The device of claim 1, wherein determining the set of parameters for the current driver comprises determining a load forward voltage based on a measured input voltage and a measured inductor voltage.

5. The device of claim 1, wherein determining the set of parameters for the current driver comprises determining an inductance.

6. The device of claim 1, wherein determining the set of parameters for the current driver comprises determining an internal propagation time.

7. The device of claim 1, wherein generating the output to the current driver comprises generating a target off-time.

8. The device of claim 1, wherein generating the output to the current driver comprises generating a target peak current set-point.

9. The device of claim 1, wherein generating the output to the current driver comprises:

outputting an initial peak current reference higher than the selected average current value;

determining a peak current based at least in part on an initial peak current reference and the initial current overshoot; and

determining at least one of a target ripple current and a target peak current set-point based at least in part on the peak current and the target average current.

10. The device of claim 9, wherein generating the output to the current driver further comprises:

determining the initial current overshoot based at least in part on an inductor voltage, an inductance, and a propagation time.

11. The device of claim 9, wherein generating the output to the current driver further comprises:

determining a target off-time based at least in part on;

at least one of the target ripple current and the target peak current set-point;

an inductance; and

a load forward voltage.

12. The device of claim 1, wherein the device is integrated in a microcontroller for controlling the current driver.

13. The device of claim 1, wherein the device is implemented as a central processing unit configured with executable software instructions.

14. The device of claim 1, wherein the device is implemented as an application-specific integrated circuit (ASIC) configured with logic-implementing circuitry hardware.

15. The device of claim 1, wherein the device is implemented as field-programmable gate array (FPGA) configured with logic-implementing circuitry hardware.

16. A method comprising:

receiving a selected average current value for a current driver;

determining a set of parameters for the current driver; and

generating an output to the current driver to cause the current driver to output a switching signal with an average current that corresponds to the selected average current value.

17. The method of claim 16, wherein generating the output to the current driver comprises:

outputting an initial peak current reference higher than the selected average current value;

determining a peak current based at least in part on an initial peak current reference and the initial current overshoot; and

determining at least one of a target ripple current and a target peak current set-point based at least in part on the peak current and the target average current.

18. The method of claim 17, wherein generating the output to the current driver further comprises:

determining the initial current overshoot based at least in part on an inductor voltage, an inductance, and a propagation time.

19. The method of claim 17, wherein generating the output to the current driver further comprises:

determining a target off-time based at least in part on;

at least one of the target ripple current and the target peak current set-point;

an inductance; and

a load forward voltage.

20. A microcontroller comprising:

a pulse density modulator;

an analog comparator;

a current control circuit having an input connected to an output of the pulse density modulator and to an output of the analog comparator; and

a logic control unit, wherein the logic control unit is configured with a peak current set-point output connected to an input of the analog comparator, and with an off-time output connected to an input of the current control unit.