POWER-SUPPLY APPARATUS

• US 20140191737A1
• Filed: 12/04/2013
• Published: 07/10/2014
• Est. Priority Date: 01/09/2013
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: NAGASAWA, Toshio, ONAYA, Yoshitaka, SAIKUSA, Koji, CHIBA, Shin
• Granted Patent: US 9,054,583 B2
• Time in Patent Office: Days
• US Class Current: 323/272
• CPC Class Codes: H02M 1/0009 Devices or circuits for detecting current in a converter
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel
• CPC Class Codes: H02M 3/1588 comprising at least one synchronous rectifier element H02M3/1582, H02M3/1584 take precedence
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A power-supply apparatus according to an aspect includes an inductor, a transistor that supplies, in an on-state, a current to the input side of the inductor, a second transistor that becomes, when the first transistor is in an off-state, an on-state and thereby brings the input side of the inductor to a predetermined potential, a signal generation unit that generates voltage signals corresponding to a current flowing to the inductor, an amplifier that outputs a current according to the voltage signals, a converter that converts the current output from the amplifier into a voltage signal, and a control unit that controls the transistors based on a first feedback signal corresponding to the voltage on the output side of the inductor and the voltage signal, which is used as a second feedback signal.

Claims

1. A power-supply apparatus comprising:

an inductor;

a first transistor that supplies, in an on-state, a current to an input side of the inductor;

a second transistor that becomes, when the first transistor is in an off-state, an on-state and thereby brings the input side of the inductor to a predetermined potential;

a signal generation unit that generates a first voltage signal corresponding to a first current flowing to the inductor;

a trans-conductance amplifier that outputs a second current according to the first voltage signal generated by the signal generation unit;

a converter that converts the second current output from the trans-conductance amplifier into a second voltage signal; and

a control unit that controls the first and second transistors based on a first feedback signal corresponding to a voltage on an output side of the inductor and the second voltage signal, the second voltage signal being used as a second feedback signal.

2. The power-supply apparatus according to claim 1, wherein the first voltage signal corresponds to a voltage difference generated by a DC resistive component of the inductor.

3. The power-supply apparatus according to claim 1, wherein

the signal generation unit comprises a CR-circuit connected in parallel with the inductor, the CR-circuit comprising a capacitive element and a first resistive element connected in series, and

the signal generation unit outputs a voltage difference across the capacitive element as the first voltage signal.

4. The power-supply apparatus according to claim 3, wherein the CR-circuit is configured so that a relation “

L1/R0=R1*C1”

is satisfied, where;

an inductance of the inductor is L1;

a DC resistive component of the inductor is R0;

a capacitance of the capacitive element is C1; and

a resistance of the first resistive element is R1.

5. The power-supply apparatus according to claim 3, wherein

one end of the first resistive element is connected to the input side of the inductor,

one end of the capacitive element is connected to the output side of the inductor,

another end of the first resistive element and another end of the capacitive element are connected to each other,

the one end of the capacitive element is connected to a non-inverting input of the trans-conductance amplifier, and

the another end of the first resistive element and the another end of the capacitive element are connected to an inverting input of the trans-conductance amplifier.

6. The power-supply apparatus according to claim 1, wherein the converter comprises a second resistive element, one end of the second resistive element being connected to an output side of the trans-conductance amplifier, another end of the second resistive element being connected to a ground.

7. The power-supply apparatus according to claim 1, further comprising a bias current source that supplies a bias current to an output side of the trans-conductance amplifier.

8. The power-supply apparatus according to claim 1, wherein when a voltage of the first feedback signal is larger than a voltage of the second feedback signal, the control unit turns on the first transistor and turns off the second transistor.

9. The power-supply apparatus according to claim 1, comprising a plurality of output stages each comprising the inductor, the first transistor, the second transistor, the signal generation unit, the trans-conductance amplifier, the converter, and the control unit.

10. The power-supply apparatus according to claim 9, wherein

the output side of each of the inductors is connected to a load, and

a clock signal having a mutually different phase and a common first feedback signal are supplied to each of the control unit.

11. The power-supply apparatus according to claim 1, comprising:

a first semiconductor chip comprising the first transistor;

a second semiconductor chip comprising the second transistor; and

a third semiconductor chip comprising the trans-conductance amplifier and the control unit.

12. The power-supply apparatus according to claim 11, wherein the first to third semiconductor chips are mounted on a same package substrate.