Voltage-doubler switched-capacitor circuit capable of detecting short circuit of flying capacitor and detection method thereof

Abstract

A voltage doubler switch capacitor circuit capable of detecting short circuit of flying capacitor and its detection method, the circuit provides a flying capacitor in parallel into the charging path, and calculate whether in the design of the charging time interval to the predetermined voltage can effectively detect whether the flying capacitor is short-circuited, if the flying capacitor is short-circuited, the current originally in the soft start stage to charge the voltage stabilizing capacitor will be shunted to the ground side of the flying capacitor short circuit, resulting in the voltage output end can not be charged to the rated voltage; if the voltage stabilizing capacitor is short-circuited, the voltage output end also can not be charged to the rated voltage, so that the voltage doubler switch capacitor circuit provides a certain timer as the electronic element of the charging time calculation in the soft start charging stage of the flying capacitor and the voltage stabilizing capacitor, if the charging time exceeds the preset time, the charging pulse will be stopped to avoid the continuous short circuit current from burning the controller, and the preset warning circuit capable of issuing short circuit warning is additionally provided on the preset circuit board of the voltage doubler switch capacitor circuit.

Description

Technical Field

[0001] This invention provides a voltage doubler switching capacitor circuit and its detection method for detecting short circuits in flying capacitors. In particular, it describes a method in which a flying capacitor is connected in parallel into the charging path in a voltage doubler switching capacitor circuit, and the predetermined voltage is calculated within the designed charging time interval to effectively detect whether the flying capacitor is short-circuited. Background Technology

[0002] Flying capacitor (C) FLY ) and voltage regulator capacitor (C) OUT These are all system components outside of integrated circuits (ICs), soldered onto circuit boards (PCBs) by assembly plants (system builders). However, occasionally, due to excessive solder or other reasons, flying capacitors (C) may malfunction. FLY The two ends form a short circuit.

[0003] Furthermore, all switches in a general circuit have on-resistance. The larger the switch area, the smaller its on-resistance, and the larger the charging current flowing through the switch. The time to charge to the rated voltage will be faster, but it is also easy to cause inrush current due to the speed, which can easily damage the load circuit. Therefore, the load circuit also needs to have a protection mechanism against inrush current.

[0004] However, although existing power circuits generally have overcurrent protection designs, if the voltage regulator capacitor (C) is used... OUT A continuous short circuit to ground at the terminal can prevent excessive instantaneous surge current. However, because of the flying capacitor (C) FLY The switches at both ends of the circuit repeatedly switch on and off, thus failing to provide continuous and effective protection against excessive current. Furthermore, current circuits do not address the issue of flying capacitors (C). FLY Short circuit protection circuit design.

[0005] Therefore, the existing circuit described above cannot detect the flying capacitor (C). FLY ) and voltage regulator capacitor (C) OUT The system is in a short-circuit state and cannot provide an effective protection mechanism, which needs to be improved and developed by those in this industry. Summary of the Invention

[0006] Therefore, in view of the above-mentioned problems and deficiencies, the inventor collected relevant information and, after multiple evaluations and considerations, designed this voltage doubler switching capacitor circuit and its detection method that can detect short circuits in flying capacitors.

[0007] The main objective of this invention is to provide a voltage doubler switching capacitor circuit capable of detecting short circuits in flying capacitors. This voltage doubler switching capacitor circuit provides a first switch (CKC) with a relatively high on-resistance, which can prevent inrush current from damaging the load circuit, thus forming a soft-start mechanism. During the soft-start phase, the flying capacitor (C) is... FLY By connecting the capacitor in parallel to the charging path and calculating whether the predetermined voltage is reached within the designed charging time interval, the flying capacitor (C) can be effectively detected. FLY Is there a short circuit? If so, check the flying capacitor (C). FLY A short circuit occurred, which was originally intended to affect the voltage regulator capacitor (C) during the soft-start phase. OUT The charging current will be diverted to the flying capacitor (C). FLY A short circuit on the ground side prevents the voltage output terminal (OUT) from charging to the rated voltage; if the voltage regulator capacitor (C) is short-circuited, the voltage output terminal (OUT) cannot be charged to the rated voltage. OUT If there is a short circuit, the voltage output terminal cannot be charged to the rated voltage. Therefore, this voltage multiplier switched capacitor circuit provides a timer as an electronic component for calculating the charging time, in the case of the flying capacitor (C). FLY ) and voltage regulator capacitor (C) OUT During the soft-start charging phase, if the charging time exceeds a preset time, the charging pulse will stop to prevent continuous short-circuit current from burning out the controller. A preset warning circuit capable of issuing a short-circuit alarm is also provided on the preset circuit board where the voltage multiplier switched capacitor circuit is located to warn of any short-circuit alarms from the flying capacitor (C) on the preset circuit board. FLY It is in a short circuit state.

[0008] A secondary objective of this invention is that the voltage multiplier switched capacitor circuit includes: a main voltage source, comprising a positive terminal and a negative terminal electrically connected to a ground side; a voltage output terminal, comprising a first output terminal and a second output terminal electrically connected to the ground side; a first switch, the two ends of which are respectively connected in series between the positive terminal of the main voltage source and the first output terminal of the voltage output terminal; two second switches, two third switches, and a flying capacitor, wherein one second switch and one third switch are connected in series between the positive terminal of the main voltage source and the first output terminal of the voltage output terminal, the other third switch and the flying capacitor are first connected in series and then connected in parallel across the two ends of the second switch, and one end of the other second switch is electrically connected between the other third switch and the flying capacitor. The other end of the capacitor is electrically connected to the ground side; a voltage regulator capacitor, the two ends of which are respectively connected across the first output terminal and the second output terminal; two logic gates, including a first logic gate that controls the conduction and disconnection of one of the two second switches, and a second logic gate that controls the conduction and disconnection of one of the two third switches; and a detection circuit, the two ends of which are respectively connected across the first output terminal and the second output terminal. The detection circuit includes a controller, at least one comparator with two voltage input terminals is electrically connected to one input side of the controller, and a charging pulse is supplied as a signal input to the input side of the controller, while the output side of the controller outputs multiple control signals that can control the first switch, the two second switches and the two third switches.

[0009] Another object of the present invention is that the detection circuit further includes a controller, an input side of which is electrically connected to at least one comparator having two voltage input terminals, and the input side of the controller is supplied with a charging pulse as a signal input, and an output side of the controller outputs a plurality of control signals that can control the first switch, the two second switches and the two third switches.

[0010] Another object of the present invention is that the comparator includes a positive input terminal and a negative input terminal. The positive input terminal is provided with two voltage divider resistors connected across the first output terminal and the second output terminal, so that the output voltage of the voltage output terminal is attenuated and then input to the two positive input terminals, while the two negative input terminals are provided with a reference voltage as an input. Attached Figure Description

[0011] Figure 1 This is a circuit diagram of the voltage multiplier switching capacitor of the present invention.

[0012] Figure 2 This is a diagram showing the first conduction state of the voltage multiplier switched capacitor circuit of the present invention.

[0013] Figure 3 This is the second conduction state diagram of the voltage multiplier switched capacitor circuit of the present invention.

[0014] Figure 4 This invention relates to a detection method for voltage multiplier switching capacitor circuits capable of detecting short circuits in flying capacitors.

[0015] Figure labeling: 1 - Voltage doubler switched capacitor circuit; VDD - Main voltage source; 11 - Positive terminal; 12 - Negative terminal; 13 - Ground side; OUT - Voltage output terminal; 14 - First output terminal; 15 - Second output terminal; CKC - First switch; CK - Second switch; CKB - Third switch; C FLY - Flying capacitor; C OUT - Stabilizing capacitor; 16- First logic gate; 161- Input terminal; 17- Second logic gate; 171- Input terminal; 2- Detection circuit; 21- Controller; 211- Input side; CLOCK- Charging pulse; 212- Output side; 2121- First switch control signal; 2122- Second switch control signal; 2123- Third switch control signal; 22- First comparator; 221- Positive input terminal; 222- Negative input terminal; 23- Second comparator; 231- Positive input terminal; 232- Negative input terminal; 24- Voltage divider resistor; VDIV- Voltage divider at the voltage output terminal; VREFA- First reference voltage; VREFB- Second reference voltage; 25- Timer; 31- Use a first switch with a larger impedance to soft-start the voltage multiplier switch capacitor circuit; 32- Turn on the first switch and turn off a second switch and a 33- The third switch is de-circuited to allow a main voltage source to charge a voltage regulator capacitor; 34- A timer in a detection circuit determines whether the charging time of the main voltage source on the voltage regulator capacitor is less than a preset time; 35- It is determined whether the voltage division at a voltage output terminal is greater than a second reference voltage of a second comparator; 36- The second switch is turned on and the third switch is de-circuited, allowing the main voltage source to charge a flying capacitor and store a voltage difference equal to the voltage of the main voltage source in the flying capacitor; 37- The second and third switches are turned on, discharging the voltage of the main voltage source across the flying capacitor to a voltage regulator capacitor connected across the voltage output terminal, so that the voltage output terminal has twice the voltage of the main voltage source; 38- It is determined whether the voltage division at a voltage output terminal is greater than a first reference voltage of a first comparator; 39- The charging pulse is turned off and a short-circuit alarm is issued; Detailed Implementation

[0016] To achieve the above objectives and effects, the technical means and structure adopted by the present invention are described in detail below with reference to the preferred embodiments of the present invention, so as to facilitate a complete understanding.

[0017] Please see Figures 1 to 3The figures show the circuit diagram of the voltage doubler switched capacitor circuit of the present invention, the first conduction state diagram of the voltage doubler switched capacitor circuit, and the second conduction state diagram of the voltage doubler switched capacitor circuit. It can be clearly seen from the figures that the circuit of the present invention mainly includes: a voltage doubler switched capacitor circuit 1 and a detection circuit 2, and their detailed structure and connection relationships are as follows:

[0018] This invention mainly provides a voltage doubler switched capacitor circuit with soft start function, and the switched-capacitor charge pump in the circuit is additionally equipped with a function to detect whether the fly capacitor is short-circuited.

[0019] A voltage doubler switching capacitor circuit capable of detecting short circuits in flying capacitors has the following circuit architecture:

[0020] The voltage doubler switched capacitor circuit 1 includes:

[0021] A main voltage source VDD includes a positive terminal 11 and a negative terminal 12 electrically connected to a ground side 13.

[0022] A voltage output terminal OUT includes a first output terminal 14 and a second output terminal 15 electrically connected to the ground side 13.

[0023] A first switch CKC, the two ends of which are respectively connected in series between the positive terminal 11 of the main voltage source VDD and the first output terminal 14 of the voltage output terminal OUT.

[0024] Two second switches CK, two third switches CKB, and a flying capacitor C FLY One of the second switches CK and one of the third switches CKB are connected in series between the positive terminal 11 of the main voltage source VDD and the first output terminal 14 of the voltage output terminal OUT. The other third switch CKB is connected to the flying capacitor C. FLY First, a series connection is formed, then a parallel connection is formed across the two ends of the second switch CK. One end of the other second switch CK is electrically connected to the other third switch CKB and the flying capacitor C. FLY And its other end is electrically connected to the grounding side 13.

[0025] A voltage regulator capacitor C OUT Its two ends are respectively connected across the first output terminal 14 and the second output terminal 15;

[0026] Two logic gates, including a first logic gate 16 that controls the on and off state of one of the two second switches CK, and a second logic gate 17 that controls the on and off state of one of the two third switches CKB.

[0027] A detection circuit 2 includes:

[0028] The detection circuit 2 is connected across the first output terminal 14 and the second output terminal 15 respectively. The detection circuit 2 includes a controller 21. Two comparators (first comparator 22 and second comparator 23) with two voltage input terminals are electrically connected to one input side 211 of the controller 21. The input side 211 of the controller 21 is supplied with a charging pulse CLOCK as a signal input. The output side 212 of the controller 21 outputs multiple control signals (first switch control signal 2121, second switch control signal 2122, and third switch control signal 2123) that can control the first switch CKC, the two second switches CK, and the two third switches CKB.

[0029] The two logic gates mentioned above are OR gates. The two input terminals 161 of the first logic gate 16 are respectively connected to the first switch control signal 2121 and the second switch control signal 2122 output from the output side 212 of the controller 21. The two input terminals 171 of the second logic gate 17 are respectively connected to the first switch control signal 2121 and the third switch control signal 2123 output from the output side 212 of the controller 21. The input and output correspondence between the first logic gate 16 and the second logic gate 17 is as follows:

[0030] First logic gate 16:

[0031]

[0032] Second logic gate 17:

[0033]

[0034] As can be seen from the two comparison tables above, the first input value and the second input value formed by the first switch control signal 2121 in combination with the second switch control signal 2122 or the third switch control signal 2123 will have an output value of 1 as long as either input value is not 0; the output value will only be 0 when both input values ​​are 0.

[0035] The two comparators (first comparator 22 and second comparator 23) mentioned above each have a positive input terminal (221, 231) and a negative input terminal (222, 232) at their respective voltage input terminals. The positive input terminals (221, 231) of the two comparators (first comparator 22 and second comparator 23) are provided with two voltage divider resistors 24 connected across the first output terminal 14 and the second output terminal 15, so that the voltage divider VDIV of the voltage output terminal between the two voltage divider resistors 24 is input to the two positive input terminals (221, 231). The two negative input terminals (222, 232) of the two comparators (first comparator 22 and second comparator 23) are respectively supplied with a first reference voltage VREFA and a second reference voltage VREFB as inputs.

[0036] The input side 211 of the aforementioned controller 21 is also electrically connected to a timer 25, which is used to determine the effect of the main voltage source VDD on the voltage regulator capacitor C. OUT Is the charging time less than a preset time?

[0037] The aforementioned voltage regulator capacitor C OUT The capacitance value is greater than the flying capacitor C. FLY And the flying capacitor C FLY The capacitance value range is for the voltage regulator capacitor C. OUT 0.5 to 0.05 times.

[0038] Please see Figure 4 The method shown is for detecting a voltage doubler switching capacitor circuit capable of detecting a short circuit in a flying capacitor, and includes the following steps:

[0039] Step 31, assemble the voltage doubler switched capacitor circuit (such as...) Figures 1-3 As shown, a soft start is performed using a first switch with a relatively large impedance.

[0040] Step 32: Turn on the first switch and turn off the second switch and the third switch to charge the stabilizing capacitor from the main voltage source.

[0041] Step 33: Use a timer in a detection circuit to determine whether the charging time of the main voltage source on the regulated capacitor is less than a preset time. If yes, proceed to step 34; if no, proceed to step 38.

[0042] Step 34: Determine whether the voltage divider at the output terminal of a voltage unit is greater than the second reference voltage of a second comparator.

[0043] Step 35: Turn on the second switch and turn off the third switch. The main voltage source charges a flying capacitor and stores a voltage difference equal to the voltage of the main voltage source in the flying capacitor.

[0044] Step 36: Turn on the second switch and the third switch, and discharge the voltage of the main voltage source of the flying capacitor to a voltage regulator capacitor connected across the voltage output terminal, so that the voltage output terminal has twice the voltage of the main voltage source.

[0045] Step 37: Determine whether the voltage divider at the output terminal is greater than the first reference voltage of the first comparator. If yes, proceed to step 39; if no, proceed to step 35.

[0046] Step 38: Turn off the charging pulse and issue a short circuit alarm.

[0047] Step 39: Turn off the charging pulse.

[0048] The voltage multiplier switched capacitor circuit in step 31 above includes: a main voltage source VDD, which includes a positive terminal 11 and a negative terminal 12 electrically connected to a ground side 13; a voltage output terminal OUT, which includes a first output terminal 14 and a second output terminal 15 electrically connected to the ground side 13; a first switch CKC, whose two ends are respectively connected in series between the positive terminal 11 of the main voltage source VDD and the first output terminal 14 of the voltage output terminal OUT; two second switches CK, two third switches CKB, and a flying capacitor C. FLY One second switch CK and one third switch CKB are connected in series between the positive terminal 11 of the main voltage source VDD and the first output terminal 14 of the voltage output terminal OUT. The other third switch CKB is connected to the flying capacitor C. FLY First, a series connection is formed, then a parallel connection is formed across the two ends of the second switch CK. One end of the other second switch CK is electrically connected to the other third switch CKB and the flying capacitor C. FLY Between them, and its other end is electrically connected to the ground side 13; a voltage regulator capacitor C OUT The first output terminal 14 and the second output terminal 15 are connected across the two ends of the controller 21. The controller 21 has a controller 21, and two comparators (first comparator 22 and second comparator 23) with two voltage input terminals are electrically connected to an input side 211 of the controller 21. The input side 211 of the controller 21 is supplied with a charging pulse CLOCK as a signal input, and the output side 212 of the controller 21 outputs multiple control signals (first switch control signal 2121, second switch control signal 2122, and third switch control signal 2123) that can control the first switch CKC, the two second switches CK and the two third switches CKB.

[0049] The two comparators (first comparator 22 and second comparator 23) mentioned above each have a positive input terminal (221, 231) and a negative input terminal (222, 232) at their respective voltage input terminals. The positive input terminals (221, 231) of the two comparators (first comparator 22 and second comparator 23) are provided with two voltage divider resistors 24 connected across the first output terminal 14 and the second output terminal 15, so that the voltage divider VDIV of the voltage output terminal between the two voltage divider resistors 24 is input to the two positive input terminals (221, 231). The two negative input terminals (222, 232) of the two comparators (first comparator 22 and second comparator 23) are respectively supplied with a first reference voltage VREFA and a second reference voltage VREFB as inputs.

[0050] The detection circuit 2 in step 33 above also includes a controller 21. Two comparators (first comparator 22 and second comparator 23) with two voltage input terminals are electrically connected to an input side 211 of the controller 21. The input side 211 of the controller 21 is supplied with a charging pulse CLOCK as a signal input, and the output side 212 of the controller 21 outputs multiple control signals (first switch control signal 2121, second switch control signal 2122, and third switch control signal 2123) that can control the first switch CKC, the two second switches CK, and the two third switches CKB.

[0051] The aforementioned voltage regulator capacitor C OUT The capacitance value is greater than the flying capacitor C. FLY And the flying capacitor C FLY The capacitance value range is for the voltage regulator capacitor C. OUT 0.5 to 0.05 times.

[0052] The problem this invention aims to solve is that the voltage multiplier switched capacitor circuit 1 provides a first switch CKC with a relatively large on-resistance, which can prevent inrush current from damaging the load circuit, thus forming a soft-start mechanism. During the soft-start phase, the flying capacitor C... FLY By connecting the charging path in parallel and calculating whether the predetermined voltage is reached within the designed charging time range, the flying capacitor C can be effectively detected. FLY Is there a short circuit? If the flying capacitor C is short-circuited... FLY Short circuit, originally during the soft start phase, the voltage regulator capacitor C should be checked. OUT The charging current will be diverted to the flying capacitor C. FLY A short circuit on the ground side prevents the voltage output terminal OUT from charging to the rated voltage; if the voltage regulator capacitor C... OUTA short circuit prevents the voltage output terminal OUT from charging to the rated voltage. Therefore, the voltage multiplier switching capacitor circuit 1 provides a timer 25 as an electronic component for calculating the charging time, across capacitor C. FLY With the voltage regulator capacitor (C) OUT During the soft-start charging phase, if the charging time exceeds a preset time, the charging pulse will be stopped to prevent the controller 21 from being burned out by a continuous short-circuit current. A preset warning circuit (not shown) capable of issuing a short-circuit alarm is also provided on the preset circuit board (not shown) where the voltage multiplier switching capacitor circuit 1 is located, to warn of the flying capacitor C on the preset circuit board. FLY It is in a short circuit state.

[0053] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Therefore, any simple modifications and equivalent structural changes made based on the description and drawings of the present invention should also be included within the scope of the present invention and are hereby stated.

[0054] In summary, the voltage multiplier switch capacitor circuit and its detection method described above, which can detect short circuits in flying capacitors, are highly practical and effective in achieving their intended purpose.

Claims

1. A voltage multiplier switching capacitor circuit capable of detecting short circuits in flying capacitors, characterized in that, include: A main voltage source, comprising a positive terminal and a negative terminal electrically connected to a ground side; A voltage output terminal, which includes a first output terminal and a second output terminal electrically connected to the ground side; A first switch, the two ends of which are respectively connected in series between the positive terminal of the main voltage source and the first output terminal of the voltage output terminal; Two second switches, two third switches, and a flying capacitor are provided. One second switch and one third switch are connected in series between the positive terminal of the main voltage source and the first output terminal of the voltage output terminal. The other third switch and the flying capacitor are first connected in series and then connected in parallel across the two ends of the second switch. One end of the other second switch is electrically connected between the other third switch and the flying capacitor, and the other end is electrically connected to the ground side. A voltage-regulating capacitor, with its two ends connected across the first output terminal and the second output terminal respectively; Two logic gates, each including a first logic gate controlling the on / off state of one of the two second switches, and a second logic gate controlling the on / off state of one of the two third switches; and A detection circuit has its two ends connected across the first output terminal and the second output terminal, respectively. The detection circuit includes a controller, and two comparators with two voltage input terminals are electrically connected to one input side of the controller. A charging pulse is supplied as a signal input to the input side of the controller, and multiple control signals controlling the first switch, the two second switches and the two third switches are output from one output side of the controller.

2. The voltage doubler switching capacitor circuit capable of detecting short circuits in flying capacitors as described in claim 1, characterized in that, The two logic gates are composed of OR gates, and the two input terminals of the first logic gate are respectively connected to the first switch control signal and the second switch control signal output by the output side of the controller, while the two input terminals of the second logic gate are respectively connected to the first switch control signal and the third switch control signal output by the output side of the controller.

3. The voltage doubler switching capacitor circuit capable of detecting short circuits in flying capacitors as described in claim 1, characterized in that, The two comparators each have a positive input terminal and a negative input terminal. The positive input terminal of the two comparators is provided with two voltage divider resistors connected across the first output terminal and the second output terminal, so that the voltage division of the voltage output terminal between the two voltage divider resistors is respectively input to the two positive input terminals of the two comparators. The two negative input terminals of the two comparators are respectively supplied with a first reference voltage and a second reference voltage as inputs.

4. The voltage doubler switching capacitor circuit capable of detecting short circuits in flying capacitors as described in claim 1, characterized in that, The controller is also electrically connected to a timer on its input side. The timer is used to determine whether the charging time of the main voltage source on the stabilizing capacitor is less than a preset time.

5. The voltage doubler switching capacitor circuit capable of detecting short circuits in flying capacitors as described in claim 1, characterized in that, The capacitance of the voltage regulator capacitor is greater than that of the flying capacitor, and the capacitance of the flying capacitor is 0.5 to 0.05 times that of the voltage regulator capacitor.

6. A method for detecting a short circuit in a voltage doubler switching capacitor circuit capable of detecting a flying capacitor, comprising using the voltage doubler switching capacitor circuit capable of detecting a short circuit in a flying capacitor as described in any one of claims 1 to 5, characterized in that, It includes the following steps: A. Use a first switch with a relatively large impedance to perform a soft start on the voltage doubler switching capacitor circuit. B. Turn on the first switch and turn off the second and third switches to charge a main voltage source into a voltage regulator capacitor. C. Use a timer in a detection circuit to determine whether the charging time of the main voltage source on the voltage regulator capacitor is less than a preset time. If yes, proceed to step D; if no, proceed to step H. D. Determine whether the voltage divider at the output terminal of a voltage is greater than the second reference voltage of a second comparator; E. Turn on the second switch and turn off the third switch, so that the main voltage source charges a flying capacitor and the flying capacitor stores a voltage difference equal to the voltage of the main voltage source. F. Turn on the second switch and the third switch, and discharge the voltage of the main voltage source of the flying capacitor to a voltage regulating capacitor connected across the voltage output terminal, so that the voltage output terminal has twice the voltage of the main voltage source. G. Determine whether the voltage divider at the output terminal is greater than the first reference voltage of the first comparator. If yes, proceed to step I; if no, proceed to step E. H. Turn off the charging pulse and issue a short circuit warning; and I. Turn off the charging pulse.

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