1000W switching power supply based on power management chip

Abstract

The utility model discloses a 1000W switching power supply based on a power management chip, which comprises the power management chip and a shell, and a circuit system is arranged in the power management chip. The circuit system comprises an output filtering and rectifying circuit, and a switch conversion circuit, an input filtering and rectifying circuit, an auxiliary power supply circuit and an isolation driving signal control circuit which are connected in sequence; a combined control circuit connected with the auxiliary power supply circuit and the isolation driving signal control circuit is arranged on one side of the output filtering and rectifying circuit; the combined control circuit comprises a dead time controller and two error amplifiers. Two error amplifiers with different functions are used for controlling the change of PWM, the output voltage is stabilized in an accurate range, and the output voltage is ensured to be stabilized in the accurate range while the output current is changed, so that the pulse width of a switch is changed to achieve the effect of stable output, and the pulse width is further matched with a high-power power switch for use.

Description

Technical Field

[0001] The utility model belongs to the technical field of switching power supplies, and particularly relates to a 1000W switching power supply based on a power management chip. Background Technique

[0002] As an emerging energy-providing device, the switching power supply has the characteristics of small volume, high efficiency, stable output voltage, etc., and is widely used in various industrial energy fields. In the industrial field, many devices require DC power supply devices with high-power output. For example, in many industrial fields such as metallurgical refining, power generation systems, laser engraving, and broadcast communication systems, the DC power supply device with a power of 1000W is the most common.

[0003] Due to the large power of the DC power supply device with a power of 1000W, ordinary switching power supplies cannot stabilize the output voltage within an accurate range, which easily causes damage to the switching power supply and the device. Content of the Utility Model

[0004] Aiming at the problem that the ordinary switching power supply in the prior art cannot control the output voltage of high-power devices within an accurate range, the utility model proposes the following technical solutions:

[0005] A 1000W switching power supply based on a power management chip includes a power management chip and a housing. A power management chip is arranged inside the switching power supply, and a circuit system is arranged inside the power management chip. The circuit system includes an output filter rectifier circuit and a switching conversion circuit, an input filter rectifier circuit, an auxiliary power supply circuit, and an isolation drive signal control circuit that are connected in sequence. A combined control circuit connected to the auxiliary power supply circuit and the isolation drive signal control circuit is arranged on one side of the output filter rectifier circuit;

[0006] The combined control circuit includes a dead time controller and two error amplifiers. The output ends of the two error amplifiers are connected to the input end of the same PWM feedback terminal, and the output end of the PWM feedback terminal is connected to the input end of the dead time controller.

[0007] As a preference of the above technical solution, the combined control circuit further includes a soft start circuit. The soft start circuit is connected to the dead time controller, and the soft start circuit is used to prevent overshoot during startup output.

[0008] As a preference of the above technical solution, the combined control circuit further includes an oscillator. The oscillator is one of an active oscillator or a slave oscillator. The oscillator is connected to the dead time controller, and the oscillator is used to provide a reference clock signal for the dead time controller.

[0009] As an optimization of the above technical solution, one of the error amplifiers is used to collect voltage signals for error amplification, and the other error amplifier is used to collect current signals for error amplification.

[0010] The beneficial effects of the present utility model are as follows:

[0011] 1. By using two error amplifiers with different functions to control the change of PWM, the output voltage is stabilized within a precise range, and while the output current changes, it is ensured that the output voltage remains stable within the precise range. Thus, the width of the switching pulse is changed to achieve the effect of output voltage stabilization, and further to match the use of a high-power power switch;

[0012] 2. With the cooperation of the set dead-time controller and two error amplifiers, while being able to limit the rising speed of the output voltage, the dead time can be controlled, enabling the duty cycle PWM to be adjusted temporarily. Thereby reducing the generation of stress in the switching device during switching, and it is not easy to damage the power switching device when powering on under full load. Description of the Drawings

[0013] Figure 1 Shows the circuit diagram of the circuit system in the embodiment;

[0014] Figure 2 Shows the circuit diagram of the combined control circuit in the embodiment;

[0015] Figure 3 Shows the connection diagram of the combined control circuit in the embodiment;

[0016] Figure 4 Shows in the embodiment Figure 3 of each part annotation diagram;

[0017] Figure 5 Shows the overall circuit diagram of the error amplifier in the embodiment;

[0018] Figure 6 Shows the circuit diagram of each part of the error amplifier in the embodiment;

[0019] Figure 7 Shows the circuit diagram of the dead-time control circuit in the embodiment;

[0020] Figure 8 Shows the circuit diagram of the soft-start circuit in the embodiment.

[0021] In the figure: 10, switching conversion circuit; 20, input filter rectifier circuit; 30, auxiliary power supply circuit; 40, isolation drive signal control circuit; 50, output filter rectifier circuit; 60, combined control circuit. Detailed Embodiment

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions of the present utility model will be clearly and completely described below in conjunction with the embodiments and the accompanying drawings of the specification.

[0023] Figures 1-7 Among them, a 1000W switching power supply based on a power management chip includes a power management chip and a housing. A power management chip is provided inside the switching power supply. A circuit system is provided inside the power management chip. The circuit system includes an output filter rectifier circuit 50 and a switching conversion circuit 0, an input filter rectifier circuit 20, an auxiliary power supply circuit 30, and an isolation drive signal control circuit 40 that are connected in sequence. A combined control circuit 60 connected to the auxiliary power supply circuit 30 and the isolation drive signal control circuit 40 is provided on one side of the output filter rectifier circuit 50;

[0024] The combined control circuit 60 includes a dead time controller and two error amplifiers. The output ends of the two error amplifiers are connected to the input end of the same PWM feedback terminal. The output end of the PWM feedback terminal is connected to the input end of the dead time controller.

[0025] The dead time (0 - 45% duty cycle) can be individually controlled by voltage (0 - 2.8V), preventing the occurrence of the common conduction phenomenon of the switching tube. Reducing the probability of damage to the converter. The duty cycle of the power supply can be adjusted to prevent the duty cycle from being too large and eliminate the problem of abnormal power supply operation.

[0026] One of the error amplifiers is used to collect voltage signals for error amplification, and the other error amplifier is used to collect current signals for error amplification.

[0027] When the output voltage stabilization loop has VO connected to the output terminal voltage, pin 1 connected to the reference terminal of KA7500, and pin 2 connected to the middle of voltage dividing resistors R1 and R2. One end of R1 is connected to VO, and one end of R2 is grounded. The formed voltage is compared with the reference voltage to form error amplification. For the output current limiting loop control, the voltage after sampling by the current limiting resistor of VO is a negative output. Pin 1 is grounded, and pin 2 is connected to the middle of voltage dividing resistors R1 and R2. One end of R1 is connected to VO, and one end of R2 is connected to the 5V reference of KA7500. The voltage formed by sampling the current limiting resistor is compared with the reference voltage to form error amplification. The voltage stabilization control mechanism of the power supply lies in these two error amplifiers. One collects voltage signals and then performs error amplification, and the other collects current signals for error amplification. After output, it is controlled at the PWM feedback terminal of pin 3.

[0028] This switching power supply uses two error amplifiers with different functions to control the change of PWM, stabilize the output voltage within a precise range, and ensure that the output voltage remains stable within the precise range while the output current changes. Thus, the pulse width of the switch is changed to achieve the effect of output voltage regulation, and then it is matched with a high-power power switch for use.

[0029] Figure 2 and Figure 8 In, the combined control circuit 60 further includes a soft start circuit. The soft start circuit is connected to the dead time controller, and the soft start circuit is used to prevent overshoot of the startup output.

[0030] The soft start circuit for preventing overshoot of the startup output: The reference voltage of pin 14 is connected to pin 4 of the dead time control through R1. One end of R2 is grounded, and the other end is connected to pin 4 to form a voltage division. Capacitor CS is connected in parallel across R1 to make the voltage at pin 4 change slowly. Thus, the duty cycle changes slowly, achieving the effect of soft start.

[0031] Figure 3 In, the combined control circuit 60 further includes an oscillator. The oscillator is one of an active oscillator or a slave oscillator. The oscillator is connected to the dead time controller, and the oscillator is used to provide a reference clock signal for the dead time controller.

[0032] Connection method of the combined control circuit 60: Pin 2 of IC2 KA7500 is connected to one end of resistor R43. The other end of R43 is connected to the reference terminals of pins 13 and 14 of IC2. One end of resistor R47 is connected to pin 2 of IC2, and the other end of R47 is grounded. Pin 1 of IC2 is connected to one end of resistor R56. The other end of resistor R56 is connected to one end of potentiometer VR1. The other end of potentiometer VR1 is connected to output OUT-. One end of resistor R52 is connected to pin 1 of IC2, and the other end of R52 is connected to one end of resistor R57. The other end of resistor R57 is connected to output OUT+. Capacitor C25 is connected in parallel across resistor R57. Capacitor C16 is connected in parallel between pins 2 and 3 of IC2. This error amplifier controls the stability of the output voltage.

[0033] Another error amplifier is used to control the influence of the output current on the output voltage regulation. One end of current-limiting sampling resistors RS2 and RS3 is grounded, and the other end is connected to output OUT-. One end of resistor R59 is connected to one end of resistors RS2 and RS3. The other end of resistor R59 is connected to pin 15 of IC2. The other end of resistor R59 is connected to one end of resistor R48. The other end of resistor R48 is connected to the reference of pins 13 and 14 of IC2. Capacitor C20 is connected between pin 12 and pins 13 and 14 of IC2. Pin 12 of IC2 is the power supply port of the VCC chip. Pin 16 of IC2 is connected to one end of resistor R46, and the other end of resistor R46 is connected to ground.

[0034] Between the dead time control circuit and the soft start circuit, the fifth pin of IC2 is connected to the oscillation time capacitor C21 to ground, and the sixth pin of IC2 is connected to the oscillation time resistor R51 to ground, forming a change in the time period. The fourth pin of IC2 is connected to one end of the resistor R45, and the other end of the resistor R45 is grounded. The fourth pin of IC2 is connected to one end of the resistor R39, and the other end of R39 is connected to the 13th and 14th pins of IC2. The capacitor C24 is connected in parallel across the resistor R39. Let the reference voltage be formed slowly. Limit the rising speed of the output voltage, and control the dead time to delay the adjustment of the duty cycle PWM. Reduce the generation of stress in the switching device during switching, and it is not easy to damage the power switching device when powering on at full load.

[0035] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it.

Claims

1. A 1000W switching power supply based on a power management chip, comprising a power management chip and a housing, wherein a circuit system is provided in the power management chip, characterized in that: The circuit system includes an output filter and rectifier circuit and a switch conversion circuit, an input filter and rectifier circuit, an auxiliary power supply circuit, and an isolated drive signal control circuit connected in sequence, and a combined control circuit connected to the auxiliary power supply circuit and the isolated drive signal control circuit is provided on one side of the output filter and rectifier circuit; The combined control circuit comprises a dead time controller and two error amplifiers, the output ends of the two error amplifiers are connected to the input end of the same PWM feedback end, and the output end of the PWM feedback end is connected to the input end of the dead time controller.

2. The 1000W switching power supply based on the power management chip according to claim 1, characterized in that: The combined control circuit further comprises a soft start circuit, which is connected to the dead time controller and is used to prevent the startup output from overshooting.

3. The 1000W switching power supply based on the power management chip according to claim 1, characterized in that: The combined control circuit further includes an oscillator, which is an active oscillator or a slave oscillator. The oscillator is connected to the dead time controller and is used to provide a reference clock signal for the dead time controller.

4. The 1000W switching power supply based on the power management chip according to claim 1, characterized in that: One of the error amplifiers is used to collect voltage signals for error amplification, and the other error amplifier is used to collect current signals for error amplification.

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