Circuit and method for power control

Patent metadata

Field	Value
Publication number	US-10534387-B2
Application number	US-201715710883-A
Country	US
Kind code	B2
Filing date	Sep 21, 2017
Priority date	Nov 20, 2015
Publication date	Jan 14, 2020
Grant date	Jan 14, 2020

Abstract

A power control integrated circuit (IC) chip can include a direct current (DC)-DC converter that outputs a switching voltage in response to a switching output enable signal. The power control IC chip can also include an inductor detect circuit that detects whether an inductor is conductively coupled to the DC-DC converter and a powered circuit component in response to an inductor detect signal. The power control IC chip can further include control logic that (i) controls the inductor detect signal based on an enable DC-DC signal and (ii) controls the switching output enable signal provided to the DC-DC converter and a linear output disable signal provided to a linear regulator based on a signal from the inductor detect circuit indicating whether the inductor is conductively coupled to the DC-DC converter and the powered circuit component.

First claim

What is claimed is:

1. A power control circuit, comprising:
a direct current (DC)-DC converter configured to receive a DC-DC converter control signal, the DC-DC converter configured to output a switching output voltage signal at a node of the DC-DC converter, while the power control circuit operates in a low-dropout (LDO) mode using a linear regulator configured to output a linear supply voltage signal;
an inductor detect circuit coupled to the node of the DC-DC converter, the inductor detect circuit configured to detect whether an inductor is coupled to the node of the DC-DC converter, in response to receiving an inductor detect enable control signal, and to output an inductor detect signal; and
control logic coupled to the DC-DC converter and to the inductor detect circuit, the control logic configured to output the DC-DC converter control signal to activate the DC-DC converter in response to both receiving a DC-DC enable signal and the inductor detect circuit outputting the inductor detect signal after determining that the inductor is coupled to the node of the DC-DC converter.

2. The power control circuit of claim 1 , wherein the DC-DC converter is configured to be coupled to a processor core.

3. The power control circuit of claim 1 , wherein the power control circuit is on a motor vehicle.

4. The power control circuit of claim 1 , wherein the inductor detect circuit detects whether the inductor is conductively coupled to the switching output voltage signal of the DC-DC converter.

5. The power control circuit of claim 4 , wherein the inductor detect circuit asserts a signal at a control node of a transistor in response to detecting whether the inductor is conductively coupled to the DC-DC converter.

6. The power control circuit of claim 5 , wherein the inductor detect circuit outputs the inductor detect signal that characterizes a presence or absence of the inductor.

7. The power control circuit of claim 1 , further comprising the linear regulator coupled to the control logic, wherein the control logic provides a linear output disable signal to the linear regulator in response to a signal from the inductor detect circuit indicating that the inductor is conductively coupled to the DC-DC converter, wherein the linear regulator disables the linear supply voltage signal in response to the linear output disable signal.

8. The power control circuit of claim 7 , wherein the linear regulator is a low-dropout (LDO) regulator.

9. The power control circuit of claim 8 , wherein the control logic causes the power control circuit to transition between operating in the LDO mode wherein the LDO regulator outputs the linear voltage supply signal and operating in a DC-DC mode wherein the DC-DC converter outputs the switching output voltage signal.

10. The power control circuit of claim 1 , wherein the DC-DC converter outputs a voltage on the switching voltage output signal that comprises a square wave.

11. The power control circuit of claim 1 , wherein the inductor is external to the power control circuit.

12. The power control circuit of claim 1 , wherein the control logic filters transient signals on the inductor detect signal from the inductor detect circuit that occur during a predetermined discharge time.

13. The power control circuit of claim 1 , wherein the control logic disables the inductor detect signal prior to enabling a switching output enable signal.

14. The power control circuit of claim 1 , wherein the control logic disables power transistors of the DC-DC converter prior to receiving the inductor detect signal indicating that the inductor is conductively coupled to the DC-DC converter.

15. A method, comprising:
receiving, by a power control circuit, a direct current (DC)-DC enable signal, while operating the power control circuit in a low-dropout (LDO) mode and supplying a low dropout voltage from a linear regulator in the power control circuit to a voltage supply output;
detecting whether an inductor is coupled to the power control circuit, in response to receiving the DC-DC enable signal; and
activating a DC-DC converter to supply a voltage to a switching voltage output signal, in response to both receiving the DC-DC enable signal and to detecting that the inductor is coupled to the power control circuit.

16. The method of claim 15 , further comprising:
deactivating the DC-DC converter in response to detecting that the inductor is not coupled to the power control circuit.

17. The method of claim 15 , further comprising:
deactivating the linear regulator, in response to detecting that the inductor is coupled to the power control circuit, transitioning the power control circuit from the LDO mode to a DC-DC mode.

18. The method of claim 15 , wherein detecting whether the inductor is coupled to the power control circuit comprises:
sensing a short between the switching voltage output signal of the DC-DC converter and the voltage supply output of the linear regulator.

19. A power control circuit, comprising:
a linear regulator coupled to a first node of an inductor, the linear regulator configured to output a supply voltage output signal;
a direct current (DC)-DC converter coupled to a second node of the inductor, the DC-DC converter configured to output a switching output voltage signal while the linear regulator outputs the supply voltage output signal;
an inductor detect circuit configured to be coupled to the second node of the inductor; and
control logic coupled to the DC-DC converter, to the linear regulator, and to the inductor detect circuit.

20. The power control circuit of claim 19 , wherein the supply voltage output signal of the linear regulator is configured to be coupled to a processor core.

Assignees

• Texas Instruments Inc

Inventors

• Turkewadikar Sachin Sudhir
• Agarwal Nitin
• Radhakrishnan Madhan

Classifications

• H02M1/36

  Means for starting or stopping converters · CPC title

• G01R33/0023

  Electronic aspects, e.g. circuits for stimulation, evaluation, control; Treating the measured signals; calibration (G01R33/0017 takes precedence) · CPC title

• H02M3/1584 Primary

  with a plurality of power processing stages connected in parallel · CPC title

• G05F1/56 Primary

  using semiconductor devices in series with the load as final control devices (G05F1/461 takes precedence) · CPC title

• H02M3/158

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