Linear power regulator device with variable transconductance driver

Patent metadata

Field	Value
Publication number	US-9651968-B2
Application number	US-201214415643-A
Country	US
Kind code	B2
Filing date	Jul 19, 2012
Priority date	Jul 19, 2012
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

The present invention pertains to a linear power regulator device that includes an internal pass device, a driver device having a driver output arranged to drive the internal pass device via the driver output. The linear power regulator device also includes an external connection connectable or connected to an external pass device; and the driver device is arranged to drive the external pass device via the driver output and the external connection.

First claim

The invention claimed is:

1. A linear voltage regulator device, comprising:
an external connection connectable, or connected, to an external pass device connected between a power source and an external load, and arranged to regulate a power provided by said power source to said external load if said external connection is connected to the external pass device;
an internal pass device connectable between the power source and the external load, and arranged to regulate said power when said external connection is not connected to the external pass device;
a driver device having a variable transconductance and arranged to drive the internal pass device and arranged to drive the external pass device via the external connection; and
a transconductance control circuitry arranged to control the variable transconductance to change depending on an output current flowing through the internal pass device and/or the external pass device, wherein
the driver device has a first mode with a first transconductance and a second mode with a second transconductance and
the transconductance control circuitry is configured to control the driver device to be in the first mode or the second mode depending on the output current flowing through one or more of the internal pass device and the external pass device transconductance.

2. The linear voltage regulator device according to claim 1 , wherein the transconductance control circuitry comprises an output current detection device arranged to determine an output current flowing through the internal pass device and/or the external pass device.

3. The linear voltage regulator device according to claim 1 wherein the driver device comprises an input stage having the variable transconductance.

4. The linear voltage regulator device according to claim 1 , the transconductance control circuitry being arranged to change the variable transconductance depending on an output current if no external pass device is connected to the linear voltage regulator device.

5. The linear voltage regulator device according to claim 1 , wherein
the first transconductance is smaller than the second transconductance, and
the transconductance control circuitry is configured to control the driver device to be in the first mode if one or more of the external pass device is connected and if a high current exceeding a predetermined threshold value flows through the internal pass device.

6. An electronic device comprising or being connected to a linear voltage regulator device according to claim 1 .

7. The linear voltage regulator device according to claim 2 , wherein the output current detection device being arranged to switch on and off one or more transistors of the driver device to change the variable transconductance of the driver device.

8. The linear voltage regulator device according to claim 3 , wherein
one or more of the driver device and the input stage comprises one or more switchable transistors, and
the switchable transistors are configured to be switched by the transconductance control circuitry to change the variable transconductance of the one or more of the driver device and the input stage.

9. The linear voltage regulator device according to claim 5 , the transconductance control circuitry being arranged to control the driver device to be in the second mode if a low current not exceeding the predetermine threshold value flows through the internal pass device.

10. The electronic device according to claim 6 , further comprising an external pass device connected to the linear voltage regulator device.

11. A method comprising:
providing an external connection at a linear voltage regulator device, the external connection connectable, or connected, to an external pass device connected between a power source and an external load;
regulating a power provided by said power source to said external load if said external connection is connected to said external pass device;
regulating said power to said external connection using an internal pass device connectable between said power source and said external load when said external connection is not connected to said external pass device;
driving, by a driver device having a variable transconductance, said internal pass device, and said external pass device via the external connection; and
controlling, using transconductance control circuitry, said variable transconductance depending on an output current flowing through said internal pass device and said external pass device, wherein
said driver device has a first mode with a first transconductance and a second mode with a second transconductance; and
said transconductance control circuitry is configured to control said driver device to be in said first mode or said second mode depending on said output current flowing through one or more of said internal pass device and said external pass device transconductance.

12. The method of claim 11 , wherein:
said first transconductance is smaller than said second transconductance; and
said transconductance control circuitry is configured to control said driver device to be in said first mode if one or more of said external pass device is connected and if a high current exceeding a predetermined threshold value flows through said internal pass device.

13. The method claim 11 , wherein said transconductance control circuitry comprises an output current detection device arranged to determine an output current flowing through said internal pass device and said external pass device.

14. The method claim 11 wherein said driver device comprises an input stage having said variable transconductance.

15. The method of claim 11 , wherein said transconductance control circuitry is arranged to change said variable transconductance depending on an output current if no external pass device is connected to said linear voltage regulator device.

16. The method claim 12 , wherein said transconductance control circuitry is arranged to control said driver device to be in said second mode if a low current not exceeding the predetermine threshold value flows through said internal pass device.

17. The method of claim 14 , wherein:
one or more of said driver device and said input stage comprises one or more switchable transistors; and
said switchable transistors are configured to be switched by said transconductance control circuitry to change said variable transconductance of the one or more of said driver device and said input stage.

18. A linear voltage regulator device, comprising:
an external connection connectable, or connected, to an external pass device connected between a power source and an external load, and arranged to regulate a power provided by said power source to said external load if said external connection is connected to the external pass device;
an internal pass device connectable between the power source and the external load, and arranged to regulate said power when said external connection is not connected to the external pass device;
a driver device having a variable transconductance and arranged to drive the internal pass device and arranged to drive the external pass device via the external connection; and
a transconductance control circuitry arranged to control the variable transconductance to change depending on an output current flowing through the internal pass device and/or the external pass device,
wherein said transconductance control circuitry comprises an output current detection device arranged to determine an output current flowing through said internal pass device and said ex

Assignees

• Pujol Alexandre
• Givelin Philippe
• Mansri Mohammed
• Nxp Usa Inc

Inventors

• Pujol Alexandre
• Givelin Philippe
• Mansri Mohammed

Classifications

• G05F1/575

  characterised by the feedback circuit · CPC title

• G05F1/59

  including plural semiconductor devices as final control devices for a single load · CPC title

• G05F1/565

  sensing a condition of the system or its load in addition to means responsive to deviations in the output of the system, e.g. current, voltage, power factor (G05F1/563 takes precedence) · CPC title

• H02M3/158

  including plural semiconductor devices as final control devices for a single load · CPC title

• G05F1/573

  with overcurrent detector · CPC title