CN112332666A - Power supply circuit with floating control function - Google Patents

Power supply circuit with floating control function Download PDF

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Publication number
CN112332666A
CN112332666A CN202011105594.4A CN202011105594A CN112332666A CN 112332666 A CN112332666 A CN 112332666A CN 202011105594 A CN202011105594 A CN 202011105594A CN 112332666 A CN112332666 A CN 112332666A
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module
transistor
power supply
electrically connected
voltage
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孙波
杨逢春
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Suzhou Kunyuan Microelectronics Co ltd
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Suzhou Kunyuan Microelectronics Co ltd
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Priority to CN202011105594.4A priority Critical patent/CN112332666A/en
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • H02M3/158—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/32—Means for protecting converters other than automatic disconnection

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)

Abstract

An embodiment of the present invention provides a power circuit with a floating control function, including: the power transistor, the driving module, the inductor, the voltage detection module, the comparison module and the energy discharge module are connected with the energy discharge module; the grid electrode of the power transistor is electrically connected with the driving module, the first pole transmits output voltage through an inductor, the second pole is connected to an input power supply, and the first pole of the power transistor is connected to the floating ground; the first end of the voltage detection module is connected to a floating power supply, the second end of the voltage detection module is connected with the floating power supply, and the third end of the voltage detection module is electrically connected with the first input end of the comparison module; the second input end of the comparison module is connected with the threshold voltage, and the output end of the comparison module is electrically connected with the control end of the energy discharge module; the first end of the energy discharge module is connected to the output voltage, and the second end of the energy discharge module is grounded. The power supply circuit with the floating control function provided by the embodiment of the invention can solve the problem of power failure of the floating power supply when the power supply circuit is in no-load.

Description

Power supply circuit with floating control function
Technical Field
The invention relates to the field of power supplies, in particular to a power supply circuit with a floating control function.
Background
With the development of electronic technology, electronic products are increasingly used. Among them, as an energy source of an electronic product, power management is an important factor for ensuring stable operation of the electronic product.
In a conventional power supply circuit, a power transistor is connected to a high-voltage power supply at one end and an inductor at the other end, so that the power transistor has a problem of withstand voltage of a gate-source voltage Vgs. In order to solve the problem, the floating power supply is connected to adjust the gate-source voltage Vgs, so that the gate-source voltage Vgs is prevented from exceeding a voltage withstanding range. The floating power supply is powered by a high-voltage power supply, when a load exists in the power supply system, the power transistor is repeatedly switched on and off, and the floating power supply in the power supply system can be intermittently powered so that the floating power supply is not powered down. When the power transistor is in idle load, the power transistor is turned off for a long time, and the floating power supply cannot be supplied with power and is powered down. Therefore, the existing power supply circuit has the problems that the floating power supply is powered off and cannot normally supply power when the power supply circuit is in no-load.
Disclosure of Invention
The power supply circuit with the floating control function provided by the embodiment of the invention is used for solving the problem of power failure of a floating power supply when the power supply circuit is in no-load.
An embodiment of the present invention provides a power circuit with a floating control function, including: the power transistor, the driving module, the inductor, the voltage detection module, the comparison module and the energy discharge module are connected with the energy discharge module;
the grid electrode of the power transistor is electrically connected with the driving module, the first pole of the power transistor transmits output voltage through the inductor, the second pole of the power transistor is connected to an input power supply, and the first pole of the power transistor is connected to a floating ground;
the first end of the voltage detection module is connected to a floating power supply, the second end of the voltage detection module is connected with the floating power supply, and the third end of the voltage detection module is electrically connected with the first input end of the comparison module; the voltage detection module is used for detecting the voltage difference between the floating power supply and the floating ground;
a second input end of the comparison module is connected with a threshold voltage, and an output end of the comparison module is electrically connected with a control end of the energy discharge module;
the first end of the energy discharge module is connected to the output voltage, and the second end of the energy discharge module is grounded; the comparison module is used for controlling the state of the energy discharge module according to the output signal of the comparison module so as to control the voltage of the floating ground.
Optionally, the voltage detection module includes a current mirror module and a current-voltage conversion module;
the current mirror module comprises a first input end, a second input end and an output end, the first input end of the current mirror module is connected with the floating ground power supply, the second input end of the current mirror module is connected with the floating ground, and the output end of the current mirror module is electrically connected with the first input end of the comparison module;
the current-voltage conversion module comprises a first end and a second end, the first end of the current-voltage conversion module is electrically connected with the output end of the current mirror image module, and the second end of the current-voltage conversion module is grounded; the current-voltage conversion module is used for converting the current of the current mirror module into voltage.
Optionally, the current mirror module includes a first transistor, a second transistor, and a first resistor;
the grid electrode of the first transistor is electrically connected with the grid electrode of the second transistor, the first pole of the first transistor is electrically connected with the first pole of the second transistor, and the second pole of the first transistor is electrically connected with the first end of the first resistor;
the first end of the first resistor is electrically connected with the grid electrode of the first crystal, and the second end of the first resistor is electrically connected with the first end of the inductor;
the first pole of the second transistor is electrically connected with the floating power supply, and the second pole of the second transistor is electrically connected with the first end of the comparison module.
Optionally, the first transistor and the second transistor are P-type transistors.
Optionally, the current-voltage conversion module includes a third transistor and a second resistor;
the grid electrode of the third transistor is electrically connected with the first end of the second resistor, the first pole of the third transistor is electrically connected with the first end of the comparison module, and the second pole of the third transistor is electrically connected with the first end of the second resistor;
and the second end of the second resistor is grounded.
Optionally, the energy discharge module comprises a fourth transistor and a third resistor;
the grid electrode of the fourth transistor is electrically connected with the output end of the comparison module, the first electrode of the fourth transistor is grounded, and the second electrode of the fourth transistor is electrically connected with the first end of the third resistor;
the second end of the third resistor is electrically connected with the output voltage.
Optionally, the power transistor is an N-type transistor.
Optionally, the power circuit provided in the embodiment of the present invention further includes a capacitor module, and the capacitor module is electrically connected between the floating power supply and the floating ground.
Optionally, the driving module includes a first end, a second end and an output end; the first end of the driving module is connected to the floating power supply, the second end of the driving module is connected to the floating ground, and the output end of the driving module is electrically connected with the grid electrode of the power transistor.
Optionally, the power circuit provided in the embodiment of the present invention further includes a switching diode, an anode of the switching diode is grounded, and a cathode of the switching diode is electrically connected to the first pole of the power transistor.
According to the embodiment of the invention, the first end of the voltage detection module is connected to a floating ground power supply, the second end of the voltage detection module is connected with the floating ground, the first pole of the power transistor is also connected to the floating ground, and the power supply circuit comprises the voltage detection module, the comparison module and the energy discharge module which are matched with each other. The voltage detection module is used for detecting the voltage difference between the floating power supply and the floating ground, the detection result is input to the first input end of the comparison module, the comparison module compares the voltage difference with the threshold voltage, and a control signal is output to control the state of the energy release module. According to the embodiment of the invention, when the floating ground voltage is higher, the floating ground voltage can be controlled to be released, so that the over-high withstand voltage of the power transistor is avoided; when the floating ground voltage is low, the input power supply is controlled to charge the floating ground, and the floating ground power supply can be charged through the floating ground, so that the floating ground power supply cannot be powered down. Therefore, the embodiment of the invention improves the problem of power failure of the floating power supply when the power supply circuit is in no-load.
Drawings
Fig. 1 is a schematic circuit diagram of a power circuit with a floating control function according to an embodiment of the present invention;
fig. 2 is a schematic circuit diagram of a power circuit with a floating control function according to another embodiment of the present invention;
fig. 3 is a schematic circuit diagram of another power circuit with a floating control function according to an embodiment of the present invention;
FIG. 4 is a diagram illustrating a relationship between a voltage difference between a floating power source and a floating ground and an output voltage in the prior art;
fig. 5 is a schematic diagram of a relationship between a floating power supply, a floating voltage difference, and an output voltage in a power circuit with a floating control function according to an embodiment of the present invention.
Detailed Description
The embodiments of the present invention will be described in further detail with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of and not restrictive on the broad invention. It should be further noted that, for convenience of description, only some structures, not all structures, relating to the embodiments of the present invention are shown in the drawings.
Fig. 1 is a schematic circuit structure diagram of a power circuit with a floating control function according to an embodiment of the present invention, and referring to fig. 1, the power circuit with a floating control function according to an embodiment of the present invention includes: the power transistor 110, the driving module 120, the inductor L, the voltage detection module 130, the comparison module 140, and the energy bleeding module 150; the gate of the power transistor 110 is electrically connected to the driving module 120, the first pole transmits the output voltage Vout through the inductor L, the second pole is connected to the input power Vin, and the first pole of the power transistor 110 is connected to the floating ground Lx; a first end of the voltage detection module 130 is connected to the floating power supply Vboot, a second end is electrically connected to the floating ground Lx, and a third end is electrically connected to a first input end of the comparison module 140; the voltage detection module 130 is configured to detect a voltage difference between the floating power supply Vboot and the floating ground Lx; a second input end of the comparison module 140 is connected to the threshold voltage Vth, and an output end is electrically connected to a control end of the energy bleeding module 150; the first end of the energy discharging module 150 is connected to the output voltage Vout, and the second end of the energy discharging module 150 is grounded; the comparison module 140 is configured to control a state of the energy discharge module 150 according to an output signal of the comparison module 140, so as to control a voltage of the floating ground Lx. Optionally, the power transistor 110 is an N-type transistor, a drain of the power transistor 110 is connected to the input power Vin, and a source thereof is electrically connected to the floating ground Lx. When the gate-source voltage of the power transistor 110 is positive and greater than its threshold voltage, the power transistor 110 is turned on.
Illustratively, the power circuit controls the floating ground Lx according to the operation principle that when the power circuit is unloaded, the power transistor 110 is turned off, the inductor L functions as a current storage, and when the voltage of the floating ground Lx is greater than the output voltage Vout, the floating ground Lx charges the inductor L with current. The comparing module 140 has a first input terminal for inputting a voltage difference between the floating power Vboot and the floating ground Lx, and the comparing module 140 is configured to compare the voltage inputted from the first input terminal with a threshold voltage Vth inputted from the second input terminal. When the input voltage of the first input terminal in the comparison module 140 is smaller than the threshold voltage value Vth accessed by the second input terminal, the comparison module 140 outputs a control signal, which can cause the energy bleeding module 150 to bleed the output voltage Vout, so as to decrease the voltage of the floating ground Lx. When the voltage of the floating ground Lx is reduced to a certain degree, the first voltage of the power transistor 110 is smaller than the gate voltage, and when the voltage difference reaches the threshold voltage Vth, the power transistor 110 is turned on, and the input power Vin supplies power to the floating ground Lx. Therefore, the embodiment of the invention can control the floating ground Lx voltage to be discharged when the floating ground Lx voltage is higher, so as to avoid the over-high withstand voltage of the power transistor 110; when the voltage of the floating ground Lx is low, the input power Vin is controlled to charge the voltage of the floating ground Lx, and the floating ground power Vboot can be charged by the voltage of the floating ground Lx, so that the floating ground power Vboot cannot be powered down.
The threshold voltage Vth can be set as required, specifically, if the threshold voltage Vth is large, the floating Lx voltage is released before being fully charged, the output voltage Vout has a slow current leakage speed, and energy waste of the input power Vin is also caused; if the threshold voltage Vth is small, the voltage of the floating ground Lx is very high, so that the input power Vin cannot continuously supply power to the floating ground power Vboot, and the problem of power failure of the floating ground power Vboot is caused. For example, the threshold voltage Vth can be calculated by computer simulation, so that the output voltage Vout can be drained quickly.
According to the embodiment of the invention, the first end of the voltage detection module 130 is connected to the floating ground power supply Vboot, the second end of the voltage detection module is electrically connected to the floating ground Lx, the first pole of the power transistor 110 is also connected to the floating ground Lx, and the power supply circuit comprises the voltage detection module 130, the comparison module 140 and the energy discharge module 150 which are matched with each other. The voltage detection module 130 is configured to detect a voltage difference between the floating power supply Vboot and the floating ground Lx, and the detected result is input to a first input terminal of the comparison module 140, and the comparison module 140 compares the voltage difference with a threshold voltage Vth and outputs a control signal to control the state of the energy bleeding module 150. According to the embodiment of the invention, when the voltage of the floating ground Lx is higher, the voltage of the floating ground Lx is controlled to be released, so that the over-high withstand voltage of the power transistor 110 is avoided; when the voltage of the floating ground Lx is low, the input power Vin is controlled to charge the floating ground Lx, and the floating ground power Vboot can be charged through the floating ground Lx, so that the floating ground power Vboot cannot be powered down. Therefore, the embodiment of the invention improves the problem of power failure of the floating power supply Vboot when the power supply circuit is in idle.
Fig. 2 is a schematic circuit structure diagram of another power circuit with a floating ground control function according to an embodiment of the present invention, and referring to fig. 2, on the basis of the foregoing embodiments, optionally, the voltage detection module 130 includes a current mirror module 131 and a current-to-voltage conversion module 132; the current mirror module 131 comprises a first input end, a second input end and an output end, the first input end of the current mirror module 131 is connected to the floating ground power supply Vboot, the second input end is connected to the floating ground Lx, and the output end is electrically connected to the first input end of the comparison module 140; the current-voltage conversion module 132 comprises a first terminal and a second terminal, the first terminal of the current-voltage conversion module 132 is electrically connected with the output terminal of the current mirror module 131, and the second terminal is grounded; the current-voltage conversion module 132 is used for converting the current of the current mirror module 131 into a voltage.
The current mirror module 131 is configured to generate a current when a voltage difference exists between the floating ground Lx and the floating ground power Vboot, and mirror the current to a first terminal of the current-voltage conversion module 132, where the current-voltage conversion module 132 generates a corresponding voltage according to the current. That is, the voltage difference between the floating ground Lx and the floating ground power Vboot-the mirror current-voltage conversion module 132 generates a one-to-one correspondence relationship. The voltage generated by the current-to-voltage conversion module 132 may be indicative of the magnitude of the voltage difference between the floating ground Lx and the floating ground power supply Vboot.
In the embodiment of the present invention, the voltage detection module 130 is arranged to include the current mirror module 131 and the current-voltage conversion module 132, so that the voltage difference between the floating ground Lx and the floating ground power supply Vboot is detected. The detected voltage difference can be compared with the threshold voltage Vth, and the magnitude relation between the voltage difference between the floating ground Lx and the floating power supply Vboot and the threshold voltage Vth can be better judged.
Fig. 3 is a schematic circuit diagram of another power circuit with a floating ground control function according to an embodiment of the present invention, and referring to fig. 3, in an embodiment of the present invention, optionally, the current mirror module 131 includes a first transistor T1, a second transistor T2, and a first resistor R1; a gate of the first transistor T1 is electrically connected to a gate of the second transistor T2, a first pole is electrically connected to a first pole of the second transistor T2, and a second pole is electrically connected to a first end of the first resistor R1; a first end of the first resistor R1 is electrically connected to the gate of the first transistor T1, and a second end is electrically connected to the first end of the inductor L; a first pole of the second transistor T2 is electrically connected to the floating power supply Vboot, and a second pole is electrically connected to a first terminal of the comparison module 140.
The first transistor T1 and the first resistor R1 are connected in series between the floating ground Lx and the floating power supply Vboot, the first transistor T1 functions as a diode, and is turned on when the voltage of the floating power supply Vboot is higher than the voltage of the floating ground Lx, and the first resistor R1 functions to limit the current. At the same time, the second transistor T2 mirrors the current of the first transistor T1.
Optionally, the first transistor and the second transistor are P-type transistors. The P-type transistor is turned on when its gate is at a low level, and is suitable for turning on when the floating power supply is higher than the floating ground voltage.
With continued reference to fig. 3, optionally, the current-voltage conversion module 132 includes a third transistor T3 and a second resistor R2; a gate of the third transistor T3 is electrically connected to the first end of the second resistor R2, a first pole is electrically connected to the first end of the comparison module 140, and a second pole is electrically connected to the first end of the second resistor R2; the second terminal of the second resistor R2 is connected to ground.
The third transistor T3 is a P-type transistor, and the connection mode of the third transistor T3 functions as a diode. When the second transistor is turned on T2, the third transistor T3 is turned on by receiving a forward voltage. A mirror current flows through the second transistor T2 in the branch formed by the third transistor T3 and the second resistor R2, which mirror current generates a voltage drop across the second resistor R2. Specifically, the larger the mirror current is, the larger the voltage drop across the second resistor R2 is, and the larger the voltage received by the comparison module 140 is; conversely, the smaller the mirror current, the lower the voltage drop across the second resistor R2, and the smaller the voltage received by the comparison module 140. Optionally, the first resistor R1 is of the same type as the second resistor R2.
With continued reference to fig. 3, based on the above embodiments, optionally, the comparing module 140 includes a comparator, a first input terminal of the comparator is connected to the threshold voltage Vth, and a second input terminal of the comparator is electrically connected to the first pole of the third transistor. Illustratively, the first input of the comparator is a positive-going input and the second input of the comparator is a negative-going input. When the voltage of the second input terminal is lower than the threshold voltage, the comparator outputs a positive voltage.
With continued reference to fig. 3, based on the above embodiments, optionally, the energy dump module 150 includes a fourth transistor T4 and a third resistor R3; the gate of the fourth transistor T4 is electrically connected to the output terminal of the comparing module 140, the first pole is grounded, and the second pole is electrically connected to the first end of the third resistor R3; a second terminal of the third resistor R3 is electrically connected to the output voltage Vout.
Illustratively, the fourth transistor T4 is an N-type transistor, and when the voltage at the second input terminal of the comparator is less than the threshold voltage Vth, the comparator outputs a positive voltage, so that the fourth transistor T4 in the energy discharging module 150 is turned on, and the output voltage Vout is discharged through the third resistor R3 and the fourth transistor T4, so that the output voltage Vout is decreased, and the voltage of the floating ground Lx is decreased.
With continued reference to fig. 3, based on the above embodiments, optionally, the driving module 120 includes a first end, a second end and an output end; the first end of the driving module 120 is connected to the floating power supply Vboot, the second end is connected to the floating ground Lx, and the output end is electrically connected to the gate of the power transistor 110.
The floating power supply Vboot serves as a power supply of the driving module 120, and the driving module 120 outputs a driving signal to the power transistor 110 by combining the voltage of the floating ground Lx and the driving logic under the action of the floating power supply Vboot. The magnitude of the driving signal is related to the magnitude of the floating power supply Vboot, and if the voltage of the floating power supply Vboot is reduced, the driving module 120 cannot drive the power transistor 110.
With continued reference to fig. 3, based on the foregoing embodiments, optionally, the power supply circuit provided in the embodiments of the present invention further includes a capacitor C electrically connected between the floating power supply Vboot and the floating ground Lx to store a voltage difference between the floating power supply Vboot and the floating ground Lx. However, due to the capacitor C, when the input power supply supplies power to the floating ground Lx, the floating power supply Vboot is boosted accordingly, thereby avoiding the problem that the power transistor 110 cannot be driven due to the lowering of the floating power supply Vboot.
With reference to fig. 3, based on the above embodiments, optionally, the power circuit provided in the embodiments of the present invention further includes a switching diode D, an anode of the switching diode D is grounded, and a cathode of the switching diode D is electrically connected to the first pole of the power transistor 110. The switching diode D is connected in anti-parallel between the first pole of the power transistor 110 and the ground. Illustratively, when the voltage of the floating ground Lx is negative, the switching diode D is turned on, and the voltage of the floating ground Lx is grounded to prevent the voltage of the floating ground Lx from being negative.
In the above embodiments, the structure of the power supply circuit is described exemplarily, and the qualitative operation principle thereof is explained in conjunction with the structure. The power supply circuit provided by the embodiment of the present invention is further explained below from a quantitative point of view.
FIG. 4 shows the prior artReferring to fig. 4, the relationship between the output voltage and the voltage difference between the floating power supply and the floating ground is schematically shown, and the time required for the maximum value of the floating power supply to fall to the threshold voltage is t0。
Wherein,
Figure BDA0002726838000000101
in the formula, CBOOT0Is the capacitance between the floating power supply and the floating ground, IBOOT0Current in the floating power supply at no load, VBOOTMAX0The maximum voltage difference between the floating power supply and the floating ground during charging. The requirement in the art is that the voltage difference between the floating power supply and the floating ground does not drop below Vth for time T0, and therefore follows:
Figure BDA0002726838000000102
in the prior art, a dummy load is added at an output voltage end to prevent the floating power supply from being used in power failure, so that the closing time of a power transistor is shortened, and the floating power supply can obtain enough electric quantity. Calculating the current required by the dummy load in the prior art as follows:
Figure BDA0002726838000000103
wherein, Cout0To output the dummy load capacitance. It can be known from the calculation that the current required by the dummy load is higher than the minimum current obtained by calculation, and therefore, the power consumption of the idle load is increased by adding the dummy load in the prior art.
Fig. 5 is a schematic diagram of a relationship structure between a voltage difference between a floating power supply and a floating ground in a power circuit with a floating control function according to an embodiment of the present invention and an output voltage, referring to fig. 3 and 5, when the voltage difference between the floating power supply Vboot and the floating ground Lx is greater than a threshold voltage Vth, the magnitude of the output voltage Vout remains unchanged, and when the voltage difference between the floating power supply Vboot and the floating ground Lx is less than the threshold voltage, the comparison module 140 outputs a control signal to the energy discharging module 150, and the energy discharging module 150 starts to discharge the voltage value of the output voltage Vout. The bleeding of the output voltage is performed during time T, so:
Figure BDA0002726838000000104
wherein C is the capacitance between the floating power supply and the floating ground, IBOOTCurrent of a floating earth power supply at no load, VBOOTMAXThe maximum voltage difference between the floating power supply and the floating ground during charging.
Further, the average current required by the load in the circuit of the embodiment of the present invention is calculated as:
Figure BDA0002726838000000111
Figure BDA0002726838000000112
in the formula, CoutIs the output load capacitance. I isdisargeTo bleed off current. The magnitude of the average current at this time can be calculated independently of R3. Meanwhile, the smaller the floating power supply current is in no load, the smaller the power consumption of the power supply circuit is, and the average current in the embodiment of the invention is the same as the calculated minimum load current. Compared with the mode of adding the dummy load in the prior art, the power supply circuit provided by the embodiment of the invention realizes the effect of lowest no-load power consumption on the basis of improving the power failure of the floating power supply when the power supply circuit is in no-load.
It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will appreciate that the embodiments of the present invention are not limited to the specific embodiments described herein, and that various obvious changes, adaptations, and substitutions are possible, without departing from the scope of the embodiments of the present invention. Therefore, although the embodiments of the present invention have been described in more detail through the above embodiments, the embodiments of the present invention are not limited to the above embodiments, and many other equivalent embodiments may be included without departing from the concept of the embodiments of the present invention, and the scope of the embodiments of the present invention is determined by the scope of the appended claims.

Claims (10)

1. A power supply circuit having a floating control function, comprising: the power transistor, the driving module, the inductor, the voltage detection module, the comparison module and the energy discharge module are connected with the energy discharge module;
the grid electrode of the power transistor is electrically connected with the driving module, the first pole of the power transistor transmits output voltage through the inductor, the second pole of the power transistor is connected to an input power supply, and the first pole of the power transistor is connected to a floating ground;
the first end of the voltage detection module is connected to a floating power supply, the second end of the voltage detection module is connected with the floating power supply, and the third end of the voltage detection module is electrically connected with the first input end of the comparison module; the voltage detection module is used for detecting the voltage difference between the floating power supply and the floating ground;
a second input end of the comparison module is connected with a threshold voltage, and an output end of the comparison module is electrically connected with a control end of the energy discharge module;
the first end of the energy discharge module is connected to the output voltage, and the second end of the energy discharge module is grounded; the comparison module is used for controlling the state of the energy discharge module according to the output signal of the comparison module so as to control the voltage of the floating ground.
2. The power supply circuit of claim 1, wherein the voltage detection module comprises a current mirror module and a current-to-voltage conversion module;
the current mirror module comprises a first input end, a second input end and an output end, the first input end of the current mirror module is connected with the floating ground power supply, the second input end of the current mirror module is connected with the floating ground, and the output end of the current mirror module is electrically connected with the first input end of the comparison module;
the current-voltage conversion module comprises a first end and a second end, the first end of the current-voltage conversion module is electrically connected with the output end of the current mirror image module, and the second end of the current-voltage conversion module is grounded; the current-voltage conversion module is used for converting the current of the current mirror module into voltage.
3. The power supply circuit according to claim 2, wherein the current mirror module comprises a first transistor, a second transistor, and a first resistor;
the grid electrode of the first transistor is electrically connected with the grid electrode of the second transistor, the first pole of the first transistor is electrically connected with the first pole of the second transistor, and the second pole of the first transistor is electrically connected with the first end of the first resistor;
the first end of the first resistor is electrically connected with the grid electrode of the first crystal, and the second end of the first resistor is electrically connected with the first end of the inductor;
the first pole of the second transistor is electrically connected with the floating power supply, and the second pole of the second transistor is electrically connected with the first end of the comparison module.
4. The power supply circuit according to claim 3, wherein the first transistor and the second transistor are P-type transistors.
5. The power supply circuit according to claim 2, wherein the current-voltage conversion module includes a third transistor and a second resistor;
the grid electrode of the third transistor is electrically connected with the first end of the second resistor, the first pole of the third transistor is electrically connected with the first end of the comparison module, and the second pole of the third transistor is electrically connected with the first end of the second resistor;
and the second end of the second resistor is grounded.
6. The power supply circuit of claim 1, wherein the energy bleed module comprises a fourth transistor and a third resistor;
the grid electrode of the fourth transistor is electrically connected with the output end of the comparison module, the first electrode of the fourth transistor is grounded, and the second electrode of the fourth transistor is electrically connected with the first end of the third resistor;
the second end of the third resistor is electrically connected with the output voltage.
7. The power supply circuit according to claim 1, wherein the power transistor is an N-type transistor.
8. The power circuit of claim 1, further comprising a capacitive module electrically connected between the floating power supply and the floating ground.
9. The power supply circuit of claim 1, wherein the driving module comprises a first terminal, a second terminal, and an output terminal; the first end of the driving module is connected to the floating power supply, the second end of the driving module is connected to the floating ground, and the output end of the driving module is electrically connected with the grid electrode of the power transistor.
10. The power supply circuit according to claim 1, further comprising a switching diode, an anode of the switching diode being grounded, and a cathode thereof being electrically connected to the first pole of the power transistor.
CN202011105594.4A 2020-10-15 2020-10-15 Power supply circuit with floating control function Pending CN112332666A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113991813A (en) * 2021-12-28 2022-01-28 深圳市永联科技股份有限公司 Voltage control method and related device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20120075958A (en) * 2010-12-29 2012-07-09 한국에너지기술연구원 Over voltage protection circuit for floating converter
CN106443502A (en) * 2016-12-06 2017-02-22 江苏理工学院 High-precision power supply ground floating port current detection and protection circuit
CN109104783A (en) * 2017-06-21 2018-12-28 通用电气照明解决方案有限公司 Driving circuit and LED light including driving circuit
CN110994987A (en) * 2019-12-30 2020-04-10 杭州必易微电子有限公司 Load driving circuit and driving method thereof and related switch control circuit
CN111682767A (en) * 2020-06-30 2020-09-18 连云港杰瑞电子有限公司 Boost circuit with fixed voltage difference

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20120075958A (en) * 2010-12-29 2012-07-09 한국에너지기술연구원 Over voltage protection circuit for floating converter
CN106443502A (en) * 2016-12-06 2017-02-22 江苏理工学院 High-precision power supply ground floating port current detection and protection circuit
CN109104783A (en) * 2017-06-21 2018-12-28 通用电气照明解决方案有限公司 Driving circuit and LED light including driving circuit
CN110994987A (en) * 2019-12-30 2020-04-10 杭州必易微电子有限公司 Load driving circuit and driving method thereof and related switch control circuit
CN111682767A (en) * 2020-06-30 2020-09-18 连云港杰瑞电子有限公司 Boost circuit with fixed voltage difference

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113991813A (en) * 2021-12-28 2022-01-28 深圳市永联科技股份有限公司 Voltage control method and related device
CN113991813B (en) * 2021-12-28 2022-03-29 深圳市永联科技股份有限公司 Voltage control method and related device

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