Power supply device including an electro-conductive cable wound around an output capacitor

Patent metadata

Field	Value
Publication number	US-9563214-B2
Application number	US-201414494744-A
Country	US
Kind code	B2
Filing date	Sep 24, 2014
Priority date	Sep 24, 2014
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

A power supply device has an output portion that generates an output voltage from an input voltage and supplies the output voltage to a load, an output feedback controller that drives the output portion by performing output feedback control, and a first detector that detects, by means of an electromagnetic induction method, a change in a first monitoring target current due to a load change. The output feedback controller reflects a detection result from the first detector into the output feedback control.

First claim

What is claimed is:

1. A power supply device, comprising:
an output portion that generates an output voltage from an input voltage and supplies the output voltage to a load;
an output feedback controller that drives the output portion by performing output feedback control; and
a first detector that detects, by means of an electromagnetic induction method, a change in a first monitoring target current due to a load change,
wherein
the output feedback controller reflects a detection result from the first detector into the output feedback control,
the first monitoring target current route is an output capacitor of the output portion; and
the magnetic coupling portion is an electro-conductive cable that is wound around the output capacitor.

2. The power supply device of claim 1 , wherein the first detector includes:
a magnetic coupling portion that magnetically couples with a first monitoring target current route where the first monitoring target current flows; and
an integrator that integrates an induced voltage or induced current which occurs in the magnetic coupling portion because of a change in the first monitoring target current and outputs an integration result to the output feedback controller.

3. The power supply device of claim 2 , wherein the integrator includes:
a current amplifier that generates an amplified current in accordance with the induced voltage or the induced current; and
a capacitor that is charged and discharged by the amplified current,
wherein a charge voltage for the capacitor is output as the detection result from the first detector.

4. The power supply device of claim 3 , wherein the integrator further includes:
a resistor that is connected in parallel with the magnetic coupling portion,
wherein the current amplifier generates the amplified current in accordance with a voltage across the resistor.

5. The power supply device of claim 3 , wherein the output feedback controller includes:
an error amplifier that generates an error voltage in accordance with a difference between the output voltage or a feedback voltage corresponding to the output voltage and a predetermined reference voltage,
wherein the capacitor is a phase compensation capacitor of the error amplifier.

6. The power supply device of claim 2 , wherein the integrator includes:
a resistor whose first terminal is connected to a first terminal of the magnetic coupling portion; and
a capacitor whose first terminal is connected to a second terminal of the resistor and whose second terminal is connected to a second terminal of the magnetic coupling portion;
wherein a node voltage appearing at a connection node between the resistor and the capacitor is output as the detection result of the first detector.

7. The power supply device of claim 1 , wherein the first monitoring target current is a first current flowing in a pre-stage of an output capacitor of the output portion, or a second current flowing in the output capacitor.

8. The power supply device of claim 1 , wherein the first monitoring target current route and the magnetic coupling portion are electric conductors adjacent to each other.

9. The power supply device of claim 8 , wherein the electric conductor is a bonding wire, a metal wiring, or a via.

10. The power supply device of claim 1 , wherein the output portion is a switching output portion which generates the output voltage from the input voltage by on/off control of an output transistor.

11. The power supply device of claim 10 , wherein the output portion is of voltage step-down type, voltage step-up type, voltage step-up/-down type, or inverting type.

12. The power supply device of claim 10 , wherein the output portion is of a synchronization rectification type or a diode rectification type.

13. The power supply device of claim 10 , wherein the output feedback controller includes:
an error amplifier that generates an error voltage in accordance with a difference between the output voltage or a feedback voltage corresponding to the output voltage and a predetermined reference voltage;
a slope voltage generator that generates a slope voltage having a triangular wave shape, a sawtooth wave shape, or an n-th order slope shape;
a clock signal generator that generates a clock signal having a predetermined switching frequency;
a comparator that compares the error voltage with the slope voltage to generate a comparison signal;
a switching controller that turns on/off the output transistor according to the clock signal and the comparison signal; and
a first adder that adds the detection result of the first detector to the error voltage.

14. The power supply device of claim 4 , wherein the output feedback controller further includes:
a sense resistor that generates a sense voltage from a switch current or an inductor current which flow in the output portion; and
a second adder that adds the sense voltage to the slope voltage.

15. The power supply device of claim 1 , wherein the output portion is a series-output configuration that generates the output voltage from the input voltage by controlling a conduction degree of an output transistor connected in series between an application terminal of the input voltage and an application terminal of the output voltage.

16. The power supply device of claim 15 , wherein the output feedback controller includes:
an operational amplifier that generates a control signal for controlling the output transistor such that the output voltage or a feedback voltage corresponding to the output voltage and a predetermined reference voltage are virtually short circuited with each other; and
an adder that adds the detection result of the first detector to the control signal.

17. The power supply device of claim 10 , further comprising:
a second detector that detects, by means of an electromagnetic induction method, a ripple component of a second monitoring target current due to the on-off control of the output transistor, wherein the output feedback controller includes:
an error amplifier that generates an error voltage in accordance with a difference between the output voltage or a feedback voltage corresponding to the output voltage and a predetermined first reference voltage;
an adder that adds the detection result of the first detector and a detection result of the second detector to the error voltage to generate an addition voltage;
a comparator that compares the addition voltage with a predetermined second reference voltage to generate a comparison signal; and
a switching controller that turns on/off the output transistor according to the comparison signal.

18. The power supply device of claim 17 , wherein the second monitoring target current is a current flowing in a pre-stage of the output capacitor of the output portion.

19. The power supply device of claim 17 , wherein the first monitoring target current and the second monitoring target current are each a current flowing in the output capacitor of the output portion.

20. The power supply device of claim 1 , further comprising:
a buffer amplifier that directly charges/discharges the output capacitor of the output portion according to the detection result of the first detector.

Assignees

• Rohm Co Ltd

Inventors

• Sumitomo Hironori

Classifications

• H02M3/156

  with automatic control of output voltage or current, e.g. switching regulators · CPC title

• G05F1/468

  characterised by reference voltage circuitry, e.g. soft start, remote shutdown · CPC title

• H02M2001/0009

  Electricity · mapped topic

• G05F1/567

  for temperature compensation · 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