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US 12,665,490 B2Granted
Converter with hold-up circuit and inrush-control circuit
AssigneeMurata Manufacturing Co., Ltd.
InventorWei Song
Life of this patent
Estimating the term…
Abstract
A holdup circuit includes a high-voltage generation circuit that outputs a high voltage and a holdup capacitor charging/discharging circuit that includes a holdup capacitor that is charged by the high voltage output by the high-voltage generation circuit. An inrush control circuit includes a constant-current source that includes a first transistor and a second transistor. During start-up, input current flows through the second transistor, and after start-up and during normal operation, the input current flows through the first transistor.
Claims17
A DC-DC converter comprising:
- an input terminal and an output terminal;
- a first stage that is connected to the input terminal and that provides a regulated voltage to a voltage bus;
- and
- a second stage including:
- a switching circuit connected to the voltage bus;
- and
- a transformer including primary and secondary windings, the primary winding is connected to the switching circuit;
- and
- a holdup circuit including:
- a voltage generation circuit that outputs a holdup-charging voltage that is larger than a voltage of the voltage bus and that includes:
- an additional transformer including primary and secondary windings;
- a driver connected to the primary winding of the additional transformer;
- and
- an oscillator that generates a symmetric square wave that is applied to the driver;
- and
- a holdup capacitor charging/discharging circuit that includes a holdup capacitor that is charged by the holdup-charging voltage output by the voltage generation circuit, wherein
- an output voltage of the holdup capacitor charging/discharging circuit is connected to the voltage bus;
- and
- the regulated voltage is maintained within a predetermined voltage range independent of variations in an input voltage applied to the input terminal.
16 more elements
A DC-DC converter comprising:
- an input terminal and an output terminal;
- a first stage that is connected to the input terminal and that provides a regulated voltage to a voltage bus;
- and
- a second stage including:
- a switching circuit connected to the voltage bus;
- and
- a transformer including primary and secondary windings, the primary winding is connected to the switching circuit;
- and
- a holdup circuit including:
- a voltage generation circuit that outputs a holdup-charging voltage that is larger than a voltage of the voltage bus;
- and
- a holdup capacitor charging/discharging circuit that includes a holdup capacitor that is charged by the holdup-charging voltage output by the voltage generation circuit;
- an inrush control circuit including:
- a first transistor;
- and
- a constant-current source that includes a second transistor;
- a third transistor connected to a gate of the first transistor;
- a fourth transistor connected to a gate of the second transistor;
- and
- a first resistor connected to the second transistor such that the input current flows through the first resistor;
- wherein
- an output voltage of the holdup capacitor charging/discharging circuit is connected to the voltage bus;
- during startup, an input current flows through the second transistor and is limited to:
- a
-
- base
- -
- emitter
-
- voltage
-
- of
-
- the
-
- fourth
-
- transistor
- a
-
- resistance
-
- of
-
- the
-
- first
-
- resistor
- ;
- after startup and during normal operation, the third transistor turns off, causing the input current to flow through the first transistor.
48 more elements
A DC-DC converter comprising:
- an input terminal and an output terminal;
- a first stage that is connected to the input terminal and that includes a control circuit that controls the first stage to provide a regulated voltage within a predetermined range to a voltage bus;
- and
- a second stage including:
- a switching circuit connected to the voltage bus;
- and
- a transformer including primary and secondary windings, the primary winding is connected to the switching circuit;
- and
- a holdup circuit including:
- a voltage generation circuit that outputs a holdup-charging voltage that is larger than a voltage of the voltage bus and that includes:
- an additional transformer including primary and secondary windings;
- a driver connected to the primary winding of the additional transformer;
- and
- an oscillator that generates a symmetric square wave that is applied to the driver;
- and
- a holdup capacitor charging/discharging circuit that includes a holdup capacitor that is charged by the holdup-charging voltage output by the voltage generation circuit, wherein
- an output voltage of the holdup capacitor charging/discharging circuit is connected to the voltage bus.
14 more elements
Dependencies are inferred from the claim text.