一种宽电压输入、四路输出DC-DC变换器

Abstract

本实用新型涉及DC‑DC变换器，具体涉及一种宽电压输入、四路输出DC‑DC变换器；包括直流电源输入端、可调输出电路和固定输出电路；可调输出电路包括第一PWM控制电路，以及与第一PWM控制电路相连的第一可调输出转换电路、第二可调输出转换电路；第一PWM控制电路通过第一输入UVLO电路、第一前端稳压电路与第一输入滤波电路相连；固定输出电路包括第二PWM控制电路，以及与第二PWM控制电路相连的第三输出转换电路、第四输出转换电路；第二PWM控制电路通过第二输入UVLO电路、第二前端稳压电路与第二输入滤波电路相连。本实用新型结构简单、设计合理且输入范围宽、电压高，功率密度大、体积小，可靠性高，实现宽电压输入、多路输出隔离DC / DC变换器，实用性较高。

Claims

1. A wide voltage input, four output DC-DC converter, characterized by: It includes a DC power input terminal (1), and an adjustable output circuit and a fixed output circuit connected to the DC power input terminal (1) through a first input filter circuit (2) and a second input filter circuit (17), respectively. The adjustable output circuit includes a first PWM control circuit (6), and a first adjustable output conversion circuit and a second adjustable output conversion circuit connected to the first PWM control circuit (6); the first adjustable output conversion circuit and the second adjustable output conversion circuit are both connected to the adjustable terminal. The first PWM control circuit (6) is connected to the first input filter circuit (2) through the first input UVLO circuit (3) and the first front-end voltage regulator circuit (4); The fixed output circuit includes a second PWM control circuit (21), and a third output conversion circuit and a fourth output conversion circuit connected to the second PWM control circuit (21); The second PWM control circuit (21) is connected to the second input UVLO circuit (18), the second front-end voltage regulator circuit (19) and the second input filter circuit (17).

2. The wide voltage input, four-output DC-DC converter of claim 1, wherein: The first adjustable output conversion circuit includes a first auxiliary power supply circuit (5), a first power switch circuit (7), a first input current sampling circuit (8), a first output voltage feedback circuit (9) connected to the first PWM control circuit (6), and a first isolation converter circuit (10) connected to the first input filter circuit (2), the first auxiliary power supply circuit (5), the first power switch circuit (7), and the first input current sampling circuit (8). A first rectifier filter circuit (11) is provided between the first isolation converter circuit (10) and the first output voltage feedback circuit (9); The second adjustable output conversion circuit includes a second power switch circuit (12), a second input current sampling circuit (13), a second output voltage feedback circuit (14) connected to the first PWM control circuit (6), and a second isolation converter circuit (15) connected to the first input filter circuit (2) and the second power switch circuit (12); A second rectifier filter circuit (16) is provided between the second isolation converter circuit (15) and the second output voltage feedback circuit (14).

3. The wide voltage input, four-output DC-DC converter of claim 2, wherein: The third output conversion circuit includes a second auxiliary power supply circuit (20), a third power switch circuit (22), a third input current sampling circuit (23), a third output voltage feedback circuit (24) connected to the second PWM control circuit (21), and a third isolation converter circuit (25) connected to the second input filter circuit (17), the second auxiliary power supply circuit (20), and the third power switch circuit (22). A third rectifier filter circuit (26) is provided between the third isolation converter circuit (25) and the third output voltage feedback circuit (24); The third power switch circuit (22) is connected to the third input current sampling circuit (23); The fourth output conversion circuit includes a fourth rectifier filter circuit (27) connected to the third isolation converter circuit (25), and a fourth output voltage regulator circuit (28) connected to the fourth rectifier filter circuit (27).

4. The wide voltage input, four-output DC-DC converter of claim 3, wherein: The DC power input terminal (1) includes a positive input terminal Vin+ and a negative input terminal Vin-, and capacitors C1 and C4 are connected in series between the positive input terminal Vin+ and the negative input terminal Vin-. The first input filter circuit (2) includes a common-mode inductor L1, and the first and third pins of the common-mode inductor L1 are connected to the negative input terminal Vin- and the positive input terminal Vin+, respectively. A capacitor C2 and a capacitor C3 are connected in parallel between the second and fourth pins of the common-mode inductor L1. The first input UVLO circuit (3) includes a Zener diode Z3. The anode of the Zener diode Z3 is connected to the second pin of the common-mode inductor L1, and the cathode of the Zener diode Z3 is connected to the first PWM control circuit (6) and connected to the fourth pin of the common-mode inductor L1 through a resistor R3. A capacitor C7 and a resistor R5 are connected in parallel between the anode and cathode of the Zener diode Z3; The first front-end voltage regulator circuit (4) includes a transistor Q3. The collector and base of the transistor Q3 are connected to the fourth pin of the common-mode inductor L1 through resistors R101 and R10, respectively. The base of transistor Q3 is grounded through Zener diode Z5 and capacitor C13; The emitter of transistor Q3 is connected to the first PWM control circuit (6) and grounded through capacitor C11; The second input filter circuit (17) includes a common-mode inductor L2, and the first and third pins of the common-mode inductor L2 are connected to the negative input terminal Vin- and the positive input terminal Vin+, respectively. A capacitor C5 and a capacitor C6 are connected in parallel between the second and fourth pins of the common-mode inductor L2. The second input UVLO circuit (18) includes a Zener diode Z4. The anode of the Zener diode Z4 is connected to the second pin of the common-mode inductor L2, and the cathode of the Zener diode Z4 is connected to the second PWM control circuit (21) and connected to the fourth pin of the common-mode inductor L2 through a resistor R4. A capacitor C8 and a resistor R6 are connected in parallel between the anode and cathode of the Zener diode Z4; The second front-end voltage regulator circuit (19) includes a transistor Q4. The collector and base of the transistor Q4 are connected to the fourth pin of the common-mode inductor L2 through resistors R102 and R16, respectively. The base of transistor Q4 is grounded through Zener diode Z6 and capacitor C23; The emitter of transistor Q4 is connected to the second PWM control circuit (21) and grounded through capacitor C15.

5. The wide voltage input, four-output DC-DC converter of claim 4, wherein: The first PWM control circuit (6) includes a PWM controller U1; The first, second, fifth, fifteenth, sixteenth, nineteenth, and twentieth pins of the PWM controller U1 are grounded through resistor R22, capacitors C24, C33, C25, C26, resistors R30, and R31, respectively. Pins 10 and 11 of the PWM controller U1 are grounded; The third pin of the PWM controller U1 is connected to the first output voltage feedback circuit (9) and grounded through the series resistor R23 and capacitor C35; The fourth pin of the PWM controller U1 is connected to the first input current sampling circuit (8) through resistor R24 ​​and grounded through capacitor C28; The sixth pin of the PWM controller U1 is connected to the cathode of the Zener diode Z3; The seventh pin of the PWM controller U1 is connected to the emitter of transistor Q3 and grounded through capacitor C34; The eighth pin of the PWM controller U1 is connected to the first power switch circuit (7) through resistor R26; The ninth pin of the PWM controller U1 is connected to one end of capacitor C32, the other end of capacitor C32 is connected to resistor R32, the other end of resistor R32 is connected to the first power switch circuit (7), and is grounded through resistor R33 and switch diode D5; The 12th pin of the PWM controller U1 is connected to one end of the capacitor C29, the other end of the capacitor C29 is connected to the resistor R29, the other end of the resistor R29 is connected to the second power switch circuit (12), and is grounded through the resistor R34 and the switching diode D4; The thirteenth pin of the PWM controller U1 is connected to the second power switch circuit (12) through resistor R27; The fourteenth pin of the PWM controller U1 is connected to the emitter of transistor Q3 and grounded through capacitor C30; The seventeenth pin of the PWM controller U1 is connected to the second input current sampling circuit (13) through resistor R28 and grounded through capacitor C27; The eighteenth pin of the PWM controller U1 is connected to the second output voltage feedback circuit (14) and grounded through the series resistor R25 and capacitor C31; The second PWM control circuit (21) includes a PWM controller U2; The first, ninth, and tenth pins of the PWM controller U2 are grounded through capacitor C12, resistor R13, and capacitor C18, respectively. The second and sixth pins of the PWM controller U2 are grounded; The third pin of the PWM controller U2 is connected to the third output voltage feedback circuit (24) and one end of the capacitor C22. The other end of the capacitor C22 is grounded through the resistor R11. The fourth pin of the PWM controller U2 is connected to the emitter of transistor Q4 and grounded through capacitor C19; The fifth pin of the PWM controller U2 is connected to the third power switch circuit (22) through resistor R17; The seventh pin of the PWM controller U2 is connected to the cathode of the Zener diode Z4; The eighth pin of the PWM controller U2 is connected to the third input current sampling circuit (23) through resistor R20 and grounded through capacitor C16.

6. The wide voltage input, four-output DC-DC converter of claim 5, wherein: The first auxiliary power supply circuit (5) includes a Zener diode Z7; The anode of Zener diode Z7 is grounded, and the cathode of Zener diode Z7 is connected to the anode of diode D18, resistor R45, and one end of capacitor C46. The cathode of diode D18 is connected to the emitter of transistor Q3; The other end of capacitor C46 is grounded; The other end of resistor R45 is connected to resistor R48, one end of capacitor C50, and the cathode of diode D9; The other end of resistor R48 and capacitor C50 is grounded, and the anode of diode D9 is connected to the first isolation converter circuit (10); The first power switching circuit (7) includes MOSFETs Q5 and Q8; The gate of MOSFET Q8 is connected to the other end of resistor R32; the source of MOSFET Q8 is grounded. The drain of MOSFET Q8 is connected to the drain of MOSFET Q5 and the first input current sampling circuit (8) through capacitor C45; The gate of MOSFET Q5 is connected to resistor R26 and grounded through resistor R47; The source of MOSFET Q5 is grounded; The first input current sampling circuit (8) includes a current transformer HG1; The first pin of the current transformer HG1 is connected to one end of the resistor R105 and the anode of the switching diode D7, and the other end of the resistor R105 is connected to the second pin of the current transformer HG1 and grounded. The cathode of the switching diode D7 is connected to one end of resistors R36, R39, R42, and capacitor C38; The other end of resistor R36 is connected to the fourth pin of common mode inductor L1, the other end of resistor R39 is connected to resistor R24 ​​and one end of resistor R43, and the other ends of resistors R43, R42 and capacitor C38 are grounded. The third pin of the current transformer HG1 is connected to the first isolation converter circuit (10); The fourth pin of the current transformer HG1 is connected to the drain of the MOSFET Q5 and the capacitor C45. The first output voltage feedback circuit (9) includes an optocoupler U3 and a precision voltage regulator U4; The first pin of the optocoupler U3 is connected to the second pin and the cathode of the precision voltage regulator U4 through resistor R40, and is connected to the first rectifier filter circuit (11) through resistor R37. The second pin of the optocoupler U3 is connected to one end of the capacitor C42. The other end of the capacitor C42 is connected to the reference terminal of the precision voltage regulator U4 and is connected to the first isolation converter circuit (10) through the resistor R46. It is connected to the adjustable terminal through the resistor R44 and is connected to the first rectifier filter circuit (11) through the series resistors R41 and R38. The third pin of optocoupler U3 is grounded; The fourth pin of optocoupler U3 is connected to the third pin of PWM controller U1; The anode of the precision voltage regulator U4 is connected to the first isolation converter circuit (10); The first isolation converter circuit (10) includes a transformer BY1; The T1.1 pin of transformer BY1 is connected to the fourth pin of common mode inductor L1 and grounded through capacitor C37; The T1.2 pin of transformer BY1 is connected to the third pin of current transformer HG1; The T1.3 pin of transformer BY1 is grounded; The T1.4 pin of transformer BY1 is connected to the anode of diode D9; The T1.5 pin of transformer BY1 is connected to one end of capacitors C43, C44, and C47. The other end of capacitors C43 and C44 is connected to the cathode of diode D6. The anode of diode D6 is connected to the T1.6 pin of transformer BY1. The other end of capacitor C47 is grounded. The T1.5 pin of transformer BY1 and the cathode of diode D6 are connected to the first rectifier filter circuit (11); The first rectifier filter circuit (11) includes a common-mode inductor L3; The first and third pins of the common mode inductor L3 are connected to pin T1.5 of transformer BY1 and the cathode of diode D6, respectively. A capacitor C39, C40, C41, C48, and a diode D8 are connected in parallel between the second and fourth pins of the common mode inductor L3. The anode of diode D8 is connected to the second pin of common-mode inductor L3, and the cathode is connected to the fourth pin of common-mode inductor L3. The second pin of the common mode inductor L3 is grounded, and the fourth pin is connected to the +5.0V / 6.8A power output terminal.

7. The wide voltage input, four-output DC-DC converter of claim 5, wherein: The second power switching circuit (12) includes MOSFETs Q6 and Q7; The gate of MOSFET Q6 is connected to the other end of resistor R29; the source of MOSFET Q6 is grounded. The drain of MOSFET Q6 is connected to the drain of MOSFET Q7 and the second isolation converter circuit (15) through capacitor C59; The gate resistor of MOSFET Q7 is R27; A resistor R58 is connected in series between the gate and source of MOSFET Q7, and the source of MOSFET Q7 is grounded through resistors R61 and R62. The second input current sampling circuit (13) includes resistors R55 and R67; One end of resistor R55 is connected to the fourth pin of common mode inductor L2, and the other end of resistor R55 is connected to one end of resistor R67 and resistor R28. The other end of resistor R67 is grounded; The second output voltage feedback circuit (14) includes an optocoupler U5 and a precision voltage regulator U6; The first pin of the optocoupler U5 is connected to the second pin and the cathode of the precision voltage regulator U6 through resistor R52, and is connected to the second rectifier filter circuit (16) through resistor R50. The second pin of the optocoupler U5 is connected to one end of the capacitor C49. The other end of the capacitor C49 is connected to the reference terminal of the precision voltage regulator U6 and grounded through resistor R56. It is connected to the adjustable terminal through resistor R54 and connected to the second rectifier filter circuit (16) through series resistors R51 and R53. The third pin of optocoupler U5 is grounded; The fourth pin of optocoupler U5 is connected to the eighteenth pin of PWM controller U1; The anode of the precision voltage regulator U6 is grounded; The second isolation converter circuit (15) includes transformer BY2; The T2.1 pin of transformer BY2 is connected to the fourth pin of common mode inductor L1 and grounded through capacitor C56; The T2.2 pin of transformer BY2 is connected to the drain of MOSFET Q7; The T2.3 pin of transformer BY2 is connected to one end of capacitors C51 and C57, as well as the second rectifier and filter circuit (16); The other end of capacitor C57 is grounded; The other end of capacitor C51 is connected to the cathode of diode D10 and the second rectifier filter circuit (16); the anode of diode D10 is connected to pin T2.4 of transformer BY2; The second rectifier filter circuit (16) includes a common-mode inductor L4; The first and third pins of the common mode inductor L4 are connected to pin T2.3 of transformer BY2 and the cathode of diode D10, respectively. A diode D11 and C52, C53, C54, C55 are connected in parallel between the second and fourth pins of the common mode inductor L4. The anode of diode D11 is connected to the second pin of common-mode inductor L4, and the cathode is connected to the fourth pin of common-mode inductor L4. The second pin of the common mode inductor L4 is grounded, and the fourth pin is connected to the +15.0V / 1.0A power output terminal.

8. The wide voltage input, four-output DC-DC converter of claim 5, wherein: The second auxiliary power supply circuit (20) includes a Zener diode Z8, diodes D16 and D17; The anode of Zener diode Z8 is grounded, the cathode of Zener diode Z8 is connected to the anode of diode D17, and the cathode of diode D17 is connected to the emitter of transistor Q4. A capacitor C78 is connected between the anode and cathode of the Zener diode Z8; The anode of diode D16 is connected to the third isolation converter circuit (25); The cathode of diode D16 is connected to the anode and cathode of Zener diode Z8 through resistors R86 and R87, respectively; The third power switching circuit (22) includes a MOSFET Q9; The drain of MOSFET Q9 is connected to one end of the third isolation converter circuit (25) and capacitor C70, and the other end of capacitor C70 is grounded through resistor R95. The gate of MOSFET Q9 is connected to resistor R17; a resistor R76 is connected between the gate and source of MOSFET Q9. The source of MOSFET Q9 is grounded through resistors R78 and R79; The third input current sampling circuit (23) includes resistors R83 and R84; One end of resistor R83 is connected to the source of MOSFET Q9, and the other end is connected to one end of resistors R20, R72, and R84. The other end of resistor R72 is connected to the fourth pin of common mode inductor L2, and the other end of resistor R84 is grounded. The third output voltage feedback circuit (24) includes an optocoupler U7 and a precision voltage regulator U8; The first pin of optocoupler U7 is grounded through resistor R59 and connected to the second pin of optocoupler U7 through resistor R66; The second pin of the optocoupler U7 is connected to the cathode of the precision voltage regulator U8 and one end of the capacitor C63. The other end of the capacitor C63 is connected to the reference terminal of the precision voltage regulator U8 and one end of the resistor R68. The other end of the resistor R68 is grounded through the resistor R60. The anode of the precision voltage regulator U8 is connected to the third rectifier filter circuit (26). The third pin of optocoupler U7 is grounded; The fourth pin of optocoupler U7 is connected to the third pin of PWM controller U2; The third isolation converter circuit (25) includes transformer BY3; The T3.1 pin of transformer BY3 is connected to the fourth pin of common mode inductor L2 and grounded through capacitor C68; The T3.2 pin of transformer BY3 is connected to the drain of MOSFET Q9; The T3.3 and T3.4 pins of transformer BY3 are connected to the third rectifier and filter circuit (26); The T3.5 and T3.6 pins of transformer BY3 are connected to the fourth rectifier and filter circuit (27), and a capacitor C69 is connected between the T3.5 and T3.8 pins of transformer BY3. The T3.8 pin of transformer BY3 is grounded. The T3.7 pin of transformer BY3 is connected to the anode of diode D16; The third rectifier filter circuit (26) includes a common-mode inductor L5; A parallel capacitor C64 and C65 are connected between the first and third pins of the common mode inductor L5. The first pin of the common mode inductor L5 is connected to the anode of the diode D13, the cathode of the diode D13 is connected to the T3.4 pin of the transformer BY3, and the third pin of the common mode inductor L5 is connected to the T3.3 pin of the transformer BY3. The second pin of common mode inductor L5 is connected to the -15.0V / 0.7A power output terminal, and the fourth pin of common mode inductor L5 is grounded; A series of capacitors C60, C61, C62, C66, resistors R69, R70, R71, and diode D12 are connected in parallel between the second and fourth pins of the common mode inductor L5. The cathode of diode D12 is grounded, and the anode of diode D12 is connected to the second pin of common-mode inductor L5.

9. The wide voltage input, four-output DC-DC converter of claim 5, wherein: The fourth rectifier filter circuit (27) includes a common-mode inductor L6; A parallel capacitor C72 and C73 are connected between the first and third pins of the common mode inductor L6. The first pin of the common mode inductor L6 is connected to the anode of the diode D15, the cathode of the diode D15 is connected to the T3.6 pin of the transformer BY3, and the third pin of the common mode inductor L6 is connected to the T3.5 pin of the transformer BY3. A series of capacitors C75, C76, and C79 are connected in parallel between the second and fourth pins of the common-mode inductor L6. The second and fourth pins of the common-mode inductor L6 are connected to the fourth output voltage regulator circuit (28); The fourth output voltage regulator circuit (28) includes a low dropout voltage regulator U9 and a Zener diode Z9; The first and second pins of the low-dropout regulator U9 are connected to the fourth pin of the common-mode inductor L6, and are connected to the cathode of the Zener diode Z9 through resistor R91. The anode of the Zener diode Z9 is connected to the third pin of the low-dropout regulator U9. The third pin of the low-dropout regulator U9 is connected to the second pin of the common-mode inductor L6. The fourth pin of the low dropout regulator U9 is grounded, and one end of resistor R75, capacitor C77, and the cathode of diode D14 are grounded. The other end of resistor R75 is connected to the fifth pin of low dropout regulator U9 through resistor R82; the other end of capacitor C77 and the anode of diode D14 are connected to the -5.0V / 0.5A power output terminal. The third pin of the low dropout regulator U9 is connected to the -5.0V / 0.5A power output terminal; The fifth pin of the low dropout regulator U9 is connected to the -5.0V / 0.5A power output terminal via resistor R85.

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