DC / DC 300W single-path output converter

Abstract

The utility model discloses a DC / DC 300W single-path output converter. The converter adopts a forward active clamping soft switching topological structure. Input direct-current voltage is filtered by the direct-current input filter circuit and connected with the primary side of the isolation transformer, the secondary side of the isolation transformer is connected with the diode rectification filter circuit, and the diode rectification filter circuit outputs a high-voltage direct-current power supply. The output high-voltage direct-current power supply provides a stable modulation signal for the pulse width modulator through the constant-current circuit; input direct-current voltage is filtered through the direct-current input filter circuit, converted into high-frequency alternating-current voltage through the main power switch tube and then coupled to a secondary side through the high-frequency transformer, and the pulse width modulator controls output of the isolation transformer through the main power switch tube. And the self-excited auxiliary power supply circuit provides a stable direct-current power supply for the pulse width modulator. The beneficial effects of the utility model are that: have the characteristics of high conversion efficiency, output low voltage heavy current, small volume, light weight, simple protection circuit, good protection effect etc.

Description

Technical Field

[0001] This utility model relates to a power supply circuit, specifically, to a DC / DC 300W single-output converter circuit. Background Technology

[0002] In recent years, due to the continuous development of distributed power supply systems, the growth rate of high-power power modules has exceeded that of primary power supplies. With the extensive use of semiconductor processes, packaging technologies, and high-frequency soft switching, power density is increasing and conversion efficiency is rising, ushering in a new era for high-power power modules.

[0003] With the rapid development of high-power power module technology, the requirements for high-power power modules in fields such as power systems, scientific experiments, and aerospace are becoming increasingly stringent. In addition to strict requirements on power density and basic electrical parameters, the reliability requirements for high-power power modules have become more stringent, and the overcurrent and short-circuit protection issues of high-power power modules have received attention.

[0004] Taking power system applications as an example, when the load of a high-power power module is inductive or capacitive, the power module output will experience prolonged overcurrent and short circuit phenomena. If the power module does not have certain protection functions, the power module feedback loop will stop working, no longer supplying power to the internal pulse width modulator. The temperature of the input voltage regulator circuit will rise sharply, losing its voltage regulation function, and ultimately burning out the pulse width modulator, causing damage to the power module. In severe cases, it will burn out downstream electrical equipment, causing unpredictable losses. Utility Model Content

[0005] This utility model is a DC / DC 300W single-output converter designed to solve the above-mentioned technical problems.

[0006] The technical solution adopted by this utility model to solve its technical problem is:

[0007] A 300W single-output DC / DC converter includes a DC input filter circuit, a self-excited auxiliary power supply circuit, a main power switch, a clamping transistor, an isolation transformer, a pulse width modulator, a diode rectifier filter circuit, and a constant current circuit. The converter employs a forward active clamp soft-switching topology. The input DC voltage (+VIN, -VIN) is filtered by the DC input filter circuit and connected to the primary winding of the isolation transformer. The secondary winding of the isolation transformer is connected to the diode rectifier filter circuit, which outputs a high-voltage DC power supply (+Vo, -Vo). The output high-voltage DC power supply (+Vo, -Vo) provides a stable modulation signal to the pulse width modulator via the constant current circuit. The input DC voltage (+VIN, -VIN) is filtered by the DC input filter circuit, converted into a high-frequency AC voltage by the main power switch, and then coupled to the secondary winding via the high-frequency transformer. The pulse width modulator controls the output of the isolation transformer through the main power switch. The self-excited auxiliary power supply circuit provides a stable DC power supply to the pulse width modulator.

[0008] The DC / DC 300W single-output converter integrates MOSFETs Q1 and Q2 as its main power switches. The gates of MOSFETs Q1 and Q2 are connected in parallel and then connected to the output of operational amplifier U2. The OUT-A pin of pulse width modulator U1 is connected to the input of operational amplifier U2. The drains of MOSFETs Q1 and Q2 are connected to the drain of clamping transistor Q3 through parallel filter capacitors C23, C24, and C25. The sources of MOSFETs Q1 and Q2 are connected to GND. The gate of clamping transistor Q3 is connected to the output of operational amplifier U3. The OUT-B pin of pulse width modulator U1 is connected to the input of operational amplifier U3. The source of clamping transistor Q3 is connected to GND.

[0009] The aforementioned DC / DC 300W single-output converter features a self-excited auxiliary power supply circuit that provides a stable DC power supply to the pulse width modulator and constant current circuit, thereby reducing excessive losses in the isolation transformer caused by supplying power to the pulse width modulator and constant current circuit.

[0010] The aforementioned 300W single-output DC / DC converter uses a low-R transistor as its main power switching transistor. DS(ON) PG-TDSON-8 packaged MOSFET.

[0011] The aforementioned 300W single-output DC / DC converter uses a low-R clamping transistor. DS(ON) PG-TDSON-8 packaged MOSFET.

[0012] This invention relates to a high-reliability, high-power, and high-efficiency switching DC / DC converter, employing a forward active clamping soft-switching topology. Both the switching transistors and clamping transistors utilize low-R... DS(ON)The PG-TDSON-8 packaged MOSFET and diode rectification structure on the secondary side enable the high-power power module to be integrated and miniaturized. Output overcurrent and short-circuit protection circuitry employs constant current protection, significantly improving reliability compared to other power modules using ordinary overcurrent and short-circuit protection circuitry, and allowing for prolonged short-circuit protection.

[0013] The working process of this invention is as follows: A DC input is passed through an inverter circuit, which causes the secondary winding of a high-frequency transformer to generate alternating current (AC). This AC current is then rectified by diodes and filtered by an inductor to become a DC output. The output voltage is automatically adjusted through output sampling, feedback, and duty cycle adjustment.

[0014] This utility model adopts a low R DS(ON) The small-package MOSFETs enable module miniaturization and reduce instantaneous power consumption during MOSFET turn-on and turn-off, providing a DC / DC 300W single-output converter.

[0015] It features high reliability, high power, and high efficiency.

[0016] Compared with traditional DC / DC converters, this invention has the following advantages:

[0017] 1. High conversion efficiency, up to 91% at 12V 25A.

[0018] 2. It has a size of only 61×58×13mm and an output power of up to 12V 300W.

[0019] 3. Constant current limiting, supporting long-term short circuits.

[0020] The advantages of this utility model are: high conversion efficiency, low voltage and high current output, small size, light weight, simple protection circuit, and good protection effect. Attached Figure Description

[0021] Figure 1 This is a functional block diagram of the circuit of this utility model;

[0022] Figure 2-1 This is one of the circuit schematic diagrams of this utility model - the pulse width modulator, main power switch, clamping transistor and isolation transformer part;

[0023] Figure 2-2 This is the second circuit schematic diagram of the present invention - the output and constant current section;

[0024] Figure 2-3 This is the third circuit schematic diagram of the present invention - a self-excited auxiliary power supply circuit. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] like Figure 1 , 2-1 As shown in Figures 2-2 and 2-3, this utility model discloses a 300W single-output DC / DC converter. The converter includes a DC input filter circuit, a self-excited auxiliary power supply circuit, a main power switch, a clamping transistor, an isolation transformer, a pulse width modulator, a diode rectifier filter circuit, and a constant current circuit. The converter adopts a forward active clamp soft-switching topology. The input DC voltage (+VIN, -VIN) is filtered by the DC input filter circuit and connected to the primary winding of the isolation transformer. The secondary winding of the isolation transformer is connected to the diode rectifier filter circuit, which outputs a high-voltage DC power supply (+Vo, -Vo). The output high-voltage DC power supply (+Vo, -Vo) provides a stable modulation signal to the pulse width modulator via the constant current circuit. The input DC voltage (+VIN, -VIN) is filtered by the DC input filter circuit, converted into a high-frequency AC voltage by the main power switch, and then coupled to the secondary winding via the high-frequency transformer. The pulse width modulator controls the output of the isolation transformer through the main power switch. The self-excited auxiliary power supply circuit provides a stable DC power supply to the pulse width modulator.

[0027] The aforementioned 300W single-output DC / DC converter integrates MOSFETs Q1 and Q2 as its main power switches. The gates of MOSFETs Q1 and Q2 are connected in parallel and then connected to the output of operational amplifier U2. The OUT-A pin of pulse width modulator U1 is connected to the input of operational amplifier U2. The drains of MOSFETs Q1 and Q2 are connected to the drain of clamping transistor Q3 through parallel filter capacitors C23, C24, and C25. The sources of MOSFETs Q1 and Q2 are connected to GND. The gate of clamping transistor Q3 is connected to the output of operational amplifier U3. The OUT-B pin of pulse width modulator U1 is connected to the input of operational amplifier U3. The source of clamping transistor Q3 is connected to GND. Figure 2-1 As shown.

[0028] The aforementioned DC / DC 300W single-output converter features a self-excited auxiliary power supply circuit that provides a stable DC power supply to the pulse width modulator and constant current circuit, thereby reducing excessive losses in the isolation transformer caused by supplying power to the pulse width modulator and constant current circuit.

[0029] The aforementioned 300W single-output DC / DC converter uses a low-R transistor as its main power switching transistor. DS(ON) PG-TDSON-8 packaged MOSFET.

[0030] The aforementioned 300W single-output DC / DC converter uses a low-R clamping transistor. DS(ON) PG-TDSON-8 packaged MOSFET.

[0031] This utility model discloses a 300W single-output DC / DC converter. After the input voltage is established, the self-excited auxiliary power supply circuit supplies power to the pulse width modulator. The DC input voltage transfers energy to the secondary winding through the primary winding of the isolation transformer and the main power switch. The AC energy generated on the secondary winding is rectified and filtered by a diode rectifier circuit to output a smooth DC voltage. When the output current exceeds the set overcurrent point or a short-circuit fault occurs, the constant current circuit starts working, and the pulse width modulator automatically adjusts the pulse width to reduce the duty cycle, allowing the power module to operate in a low-loss state. The self-excited auxiliary circuit continuously provides voltage to the pulse width modulator. When the fault is cleared, the power module output will return to normal.

[0032] This utility model is not limited to the above-described preferred embodiments. Any other products that are the same as or similar to this utility model and derived by anyone under the guidance of this utility model shall fall within the protection scope of this utility model.

Claims

1. A DC / DC 300W single-channel output converter, the converter comprising a direct current input filter circuit, a self-excitation auxiliary power supply circuit, a main power switch tube, a clamping tube, an isolation transformer, a pulse width modulator, a diode rectifier filter circuit and a constant current circuit; characterized in that: The converter adopts a forward active clamping soft switching topological structure; input direct current voltage (+VIN, -VIN) is connected with the primary of a direct current input filter circuit and an isolation transformer through filtering and isolation, the secondary of the isolation transformer is connected with a diode rectifier filter circuit, and the diode rectifier filter circuit outputs a high-voltage direct current power supply (+Vo, -Vo); the output high-voltage direct current power supply (+Vo, -Vo) provides a stable modulation signal for a pulse width modulator through a constant current circuit; the input direct current voltage (+VIN, -VIN) is filtered by the direct current input filter circuit, is converted into a high-frequency alternating current voltage through a main power switch tube, is coupled to the secondary through a high-frequency transformer, and the pulse width modulator controls the output of the isolation transformer through the main power switch tube; and the self-excited auxiliary power supply circuit provides a stable direct current power supply for the pulse width modulator.

2. A DC / DC 300W single-output converter according to claim 1, characterized in that: The main power switch tube integrates MOS tubes Q1 and Q2, the gates of the MOS tubes Q1 and Q2 are connected with the output end of an operational amplifier U2 after being connected in parallel, the OUT-A foot of the pulse width modulator U1 is connected with the input of the operational amplifier U2; the drains of the MOS tubes Q1 and Q2 are connected with the drain of a clamping tube Q3 through parallel filter capacitors C23, C24 and C25, the sources of the MOS tubes Q1 and Q2 are connected with GND; the gate of the clamping tube Q3 is connected with the output of the operational amplifier U3, the OUT-B foot of the pulse width modulator U1 is connected with the input end of the operational amplifier U3, and the source of the clamping tube Q3 is connected with GND.

3. A DC / DC 300W single-output converter according to claim 1, characterized in that: The self-excited auxiliary power supply circuit provides a stable direct current power supply for the pulse width modulator and the constant current circuit, so as to reduce the excessive loss of the isolation transformer for supplying power to the pulse width modulator and the constant current circuit.

4. The DC / DC 300W single-output converter of claim 1, wherein: The main power switch tube adopts low R DS(ON) PG-TDSON-8 package MOS tube.

5. The DC / DC 300W single-output converter of claim 1, wherein: The clamp tube adopts low R DS(ON) PG-TDSON-8 package MOS tube.

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