Multifunction DC to DC driver

Patent metadata

Field	Value
Publication number	US-9763296-B1
Application number	US-201615183551-A
Country	US
Kind code	B1
Filing date	Jun 15, 2016
Priority date	Jun 15, 2016
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

In one example, a system includes a load module, a voltage module, and a controller. The load module is configured to selectively bypass each load unit of a plurality of load units to form a series string of load units. The voltage module is configured to output a voltage across the series string of load units that is based on a target voltage. The controller is configured to output an indication of the target voltage, estimate a time delay for switching one or more load units of the plurality of load units, and output, after outputting the indication of the target voltage for the time delay, a control signal to switch one or more load units of the plurality of load units such that the series string of load units has the target quantity of load units.

First claim

The invention claimed is:

1. A voltage control system comprising:
a load module configured to selectively bypass each load unit of a plurality of load units to form a series string of load units;
a voltage module configured to receive, at a control input of the voltage module, an indication of a target voltage and supply an output voltage across the series string of load units that is based on the target voltage; and
a controller configured to:
determine a target quantity of load units used to form the series string of load units, the target quantity of load units being different from a current quantity of load units used to form the series string of load units;
determine the target voltage based on the target quantity of load units;
output, to the control input of the voltage module, the indication of the target voltage;
estimate a time delay for switching one or more load units of the plurality of load units such that the series string of load units has the target quantity of load units; and
output, after outputting the indication of the target voltage for the time delay and to the load module, a control signal to switch one or more load units of the plurality of load units such that the series string of load units has the target quantity of load units.

2. The voltage control system according to claim 1 , wherein the controller is further configured to:
estimate the time delay for switching one or more load units of the plurality of load units such that the series string of load units has the target quantity of load units based on the target voltage.

3. The voltage control system according to claim 2 , further comprising:
a capacitor,
wherein the voltage module comprises:
a compensator configured to supply energy to the capacitor based on the indication of the target voltage; and
a modulator configured to control the output voltage across the series string of load units based on a voltage of the capacitor.

4. The voltage control system according to claim 3 , wherein the controller is further configured to:
receive an indication of the voltage of the capacitor; and
estimate the time delay for switching one or more load units of the plurality of load units in the series string of load units based further on the voltage of the capacitor and a capacitance of the capacitor.

5. The voltage control system according to claim 4 , wherein:
the modulator is configured to control the output voltage across the series string of load units based on the voltage of the capacitor by outputting a switching signal indicating a duty cycle that is based on the voltage of the capacitor, and
the voltage module further comprises:
one or more energy storage elements; and
a switching unit configured to selectively switch the one or more energy storage elements using the switching signal.

6. The voltage control system according to claim 1 , wherein:
the plurality of load units is a plurality of light emitting diodes;
the target quantity of load units is a target quantity of light emitting diodes;
the series string of load units is a series string of light emitting diodes; and
determining the target quantity of load units used to form the series string of load units comprises:
in response to determining that a headlight mode of the system corresponds to a high beam mode, determining the target quantity of light emitting diodes according to a quantity of light emitting diodes associated with the high beam mode; and
in response to determining that a headlight mode of the system corresponds to a low beam mode, determining the target quantity of light emitting diodes according to a quantity of light emitting diodes associated with the low beam mode.

7. A voltage control method comprising:
determining, by a processor, a target quantity of load units used to form the series string of load units, the target quantity of load units being different from a current quantity of load units used to form the series string of load units;
determining, by the processor, a target voltage based on the target quantity of load units;
outputting, by the processor and to a voltage module configured to supply an output voltage across the string of load units that is based on the target voltage, an indication of the target voltage;
estimating, by the processor, a time delay for switching one or more load units such that the series string of load units has the target quantity of load units; and
outputting, by the processor and to the load module, after outputting the indication of the target voltage for the time delay, a control signal to switch one or more load units such that the series string of load units has the target quantity of load units.

8. The voltage control method according to claim 7 , further comprising:
estimating, by the processor, the time delay for switching one or more load units such that the series string of load units has the target quantity of load units based on the target voltage.

9. The voltage control method according to claim 8 , further comprising:
receiving, by the processor, an indication of a voltage of a capacitor, the voltage module being configured to control the output voltage across the series string of load units based on the voltage of the capacitor,
wherein the estimating of the time delay for switching one or more load units such that the series string of load units has the target quantity of load units is further based on the voltage of the capacitor.

10. The voltage control method according to claim 9 , wherein the estimating of the time delay for switching one or more load units such that the series string of load units has the target quantity of load units is further based on a capacitance of the capacitor.

11. The voltage control method according to claim 10 , further comprising:
determining, by the processor, an indication of a current flowing from the capacitor,
wherein the estimating of the time delay for switching one or more load units such that the series string of load units has the target quantity of load units is further based on the current flowing from the capacitor.

12. The voltage control method according to claim 11 , further comprising:
determining, by the processor, a difference between the target voltage and the voltage of the capacitor,
wherein the estimating of the time delay for switching one or more load units such that the series string of load units has the target quantity of load units is further based on the difference between the target voltage and the voltage of the capacitor.

13. The voltage control method according to claim 7 , further comprising:
outputting, by the processor, after outputting the indication of the target voltage and before outputting the control signal to switch one or more load units such that the series string of load units has the target quantity of load units, a control signal to switch one or more load units such that the series string of load units has the current quantity of load units.

14. A voltage control circuit comprising:
a load module configured to selectively bypass each load unit of a plurality of load units to form a series string of load units;
a voltage module configured to supply an output voltage across the series string of load units that is based on a voltage of a capacitor; and
a feedforward module configured to:
receive an indication of a current quantity of load units used to form the series string of load units;
receive an indication of a target quantity of load units used to form the series string of load units, the target quantity of load units being different from the current quantity of load units of t

Assignees

• Infineon Technologies Ag

Inventors

• Milanesi Paolo
• Penzo Roberto
• Galvano Maurizio
• Fragiacomo Fabio

Classifications

• H05B45/48

  having LEDs organised in strings and incorporating parallel shunting devices · CPC title

• H05B45/44

  with an active control inside an LED matrix · CPC title

• H05B45/10

  Controlling the intensity of the light · CPC title

• H05B45/46

  having LEDs disposed in parallel lines · CPC title

• H05B33/0824

  Electricity · mapped topic