Hardware power supply protection system built based on comparator

Abstract

The utility model relates to the technical field of hardware power supply protection, in particular to a hardware power supply protection system built based on a comparator, which comprises a monitored power supply, a first comparison module, a second comparison module, a comparison voltage module and a switching circuit module, the first comparison module comprises a comparator U4B, and the second comparison module comprises a comparator U4A; a monitored power supply is respectively connected with the reverse input end of the comparator U4B and the non-inverting input end of the comparator U4A, and the non-inverting input end of the comparator U4B and the reverse input end of the comparator U4A are respectively connected with the comparison voltage module. The switching circuit module comprises a first switching circuit and a second switching circuit, the output end of the comparator U4B is connected with the first switching circuit, and the output end of the comparator U4A is connected with the second switching circuit. According to the characteristics of the comparators, two groups of comparators are adopted to compare the upper limit and the lower limit of the voltage input by the power supply, thereby being safer, simple in structure and low in cost.

Description

Technical Field

[0001] The utility model relates to the technical field of hardware protection systems, and particularly relates to a hardware power protection system built based on a comparator. Background Art

[0002] At present, the power protection systems existing on the market generally adopt the method of TVS or zener diodes. When the power supply exceeds the voltage of the TVS or zener diode, the voltage is clamped by the TVS or zener diode, avoiding the risk of excessive voltage.

[0003] The above judgment conditions have the following problems.

[0004] 1. When the voltage is too high and the current is large, the TVS or zener diode is easily burned out.

[0005] 2. It can only prevent the problem of excessive voltage, and for the unstable state of the system when the voltage is too low, the system cannot provide protection.

[0006] Therefore, there is an urgent need for a hardware power protection system built based on a comparator, which can compare the upper and lower limits of the power supply input. When the upper and lower limits of the power supply input exceed the safe range, the switch is turned off to achieve power protection. Content of the Utility Model

[0007] To overcome the problems existing in the prior art, the purpose of the utility model is to provide a hardware power protection system built based on a comparator.

[0008] To achieve the above purpose, the utility model provides the following technical solution: A hardware power protection system built based on a comparator, including a power supply to be monitored, a first comparison module, a second comparison module, a comparison voltage module and a switch circuit module; the first comparison module includes a comparator U4B, and the second comparison module includes a comparator U4A;

[0009] The power supply to be monitored is respectively connected to the reverse input end of the comparator U4B and the non-inverting input end of the comparator U4A, and the non-inverting input end of the comparator U4B and the reverse input end of the comparator U4A are respectively connected to the comparison voltage module;

[0010] The switch circuit module includes a first switch circuit and a second switch circuit. The output end of the comparator U4B is connected to the first switch circuit, and the output end of the comparator U4A is connected to the second switch circuit.

[0011] The present utility model is further configured as follows: the first comparison module further includes a resistor R28, a resistor R31, and a capacitor C137; the first end of the resistor R28 is connected to the monitored power supply, the second end of the resistor R28 is connected to the first end of the resistor R31, the second end of the resistor R31 is grounded; the capacitor C137 is connected in parallel across the resistor R31; the inverting input terminal of the comparator U4B is connected between the capacitor C137 and the second end of the resistor R28.

[0012] The present utility model is further configured as follows: the second comparison module further includes a resistor R32, a resistor R33, and a capacitor C139; the first end of the resistor R32 is connected to the monitored power supply, the second end of the resistor R32 is connected to the first end of the resistor R33, the second end of the resistor R33 is grounded; the capacitor C139 is connected in parallel across the resistor R33, and the non-inverting input terminal of the comparator U4A is connected between the capacitor C139 and the second end of the resistor R32.

[0013] The present utility model is further configured as follows: the second comparison module further includes a resistor R35 and a capacitor C29; the first end of the resistor R35 is connected to the positive power input terminal of the comparator U4B, the second end of the resistor R35 is connected to an external main board circuit; the first end of the capacitor C29 is connected to the positive power input terminal of the comparator U4B, and the second end of the capacitor C29 is grounded.

[0014] The present utility model is further configured as follows: the negative power input terminal of the comparator U4B is grounded.

[0015] The present utility model is further configured as follows: the comparison voltage module includes a constant voltage power supply 1V8_VCC, a resistor R29, a resistor R159, and a capacitor C27; the first end of the resistor R29 is connected to the constant voltage power supply 1V8_VCC, the second end of the resistor R29 is connected to the first end of the resistor R159, the second end of the resistor R159 is grounded; the second end of the resistor R159 is connected to the first end of the capacitor C27, and the second end of the capacitor C27 is connected to the second end of the resistor R29.

[0016] The second end of the capacitor C27 is respectively connected to the non-inverting input terminal of the comparator U4B and the inverting input terminal of the comparator U4A.

[0017] The present utility model is further configured as follows: The first switch circuit includes a capacitor C26, a resistor R30, a resistor R26, and a MOS transistor Q4A; the output terminal of the comparator U4B is respectively connected to the first terminal of the capacitor C26, the first terminal of the resistor R30, and the G pole of the MOS transistor Q4A; the second terminal of the capacitor C26 and the second terminal of the resistor R30 are both grounded; the S pole of the MOS transistor Q4A is grounded; the D pole of the MOS transistor Q4A is connected to the first terminal of the resistor R26, the second terminal of the resistor R26 is connected to an external power supply, and the D pole of the MOS transistor Q4A is connected to the system output terminal of the hardware power protection system.

[0018] The present utility model is further configured as follows: The second switch circuit includes a capacitor C28, a resistor R34, and a MOS transistor Q4B; the output terminal of the comparator U4A is respectively connected to the first terminal of the capacitor C28, the first terminal of the resistor R34, and the G pole of the MOS transistor Q4B; the second terminal of the capacitor C28 and the second terminal of the resistor R34 are both grounded; the S pole of the MOS transistor Q4B is grounded; the D pole of the MOS transistor Q4B is connected to the system output terminal of the hardware power protection system.

[0019] Compared with the prior art, the present utility model has the following beneficial effects:

[0020] According to the characteristic of the comparator that when V+ > V−, the output is high level, and vice versa, the present utility model adopts two groups of comparators to respectively compare the upper limit and the lower limit of the voltage input to the power supply. When the voltage exceeds the appropriate voltage range, the system hardware shuts down, which is safer, has a simple structure, and low cost. It solves the problems of the unstable state of the existing structure when the voltage is too low, the system cannot be protected, and the voltage regulator tube is burned out when the voltage is too high.

[0021] A comparison voltage module is set, which can flexibly adjust the preset power supply range and combine with the first comparison module and the second comparison module to compare the power supply range, so the application range is wider. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 FIG. is the circuit schematic diagram of the hardware power protection system based on the comparator built in the embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The technical solution of the present utility model will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are not all the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0025] Embodiment:

[0026] As Figure 1 shown, a preferred embodiment provided by the present utility model is a hardware power protection system built based on a comparator, including a power supply to be monitored, a first comparison module, a second comparison module, a comparison voltage module, and a switching circuit module; the first comparison module includes a comparator U4B, and the second comparison module includes a comparator U4A;

[0027] The power supply to be monitored is respectively connected to the reverse input terminal of the comparator U4B and the non-inverting input terminal of the comparator U4A, and the non-inverting input terminal of the comparator U4B and the reverse input terminal of the comparator U4A are respectively connected to the comparison voltage module;

[0028] The first comparison module further includes a resistor R28, a resistor R31, and a capacitor C137; the first end of the resistor R28 is connected to the power supply to be monitored, the second end of the resistor R28 is connected to the first end of the resistor R31, and the second end of the resistor R31 is grounded; the capacitor C137 is connected in parallel across the resistor R31; the reverse input terminal of the comparator U4B is connected between the capacitor C137 and the second end of the resistor R28.

[0029] The second comparison module further includes a resistor R32, a resistor R33, and a capacitor C139; the first end of the resistor R32 is connected to the power supply to be monitored, the second end of the resistor R32 is connected to the first end of the resistor R33, and the second end of the resistor R33 is grounded; the capacitor C139 is connected in parallel across the resistor R33, and the non-inverting input terminal of the comparator U4A is connected between the capacitor C139 and the second end of the resistor R32.

[0030] The second comparison module further includes a resistor R35 and a capacitor C29; the first end of the resistor R35 is connected to the positive power input terminal of the comparator U4B, and the second end of the resistor R35 is connected to an external main board circuit; the first end of the capacitor C29 is connected to the positive power input terminal of the comparator U4B, and the second end of the capacitor C29 is grounded. The negative power input terminal of the comparator U4B is grounded.

[0031] The comparison voltage module includes a constant voltage power supply 1V8_VCC, a resistor R29, a resistor R159, and a capacitor C27; the first end of the resistor R29 is connected to the constant voltage power supply 1V8_VCC, the second end of the resistor R29 is connected to the first end of the resistor R159, and the second end of the resistor R159 is grounded; the second end of the resistor R159 is connected to the first end of the capacitor C27, and the second end of the capacitor C27 is connected to the second end of the resistor R29.

[0032] The second end of the capacitor C27 is respectively connected to the non-inverting input terminal of the comparator U4B and the inverting input terminal of the comparator U4A.

[0033] The switch circuit module includes a first switch circuit and a second switch circuit. The output terminal of the comparator U4B is connected to the first switch circuit, and the output terminal of the comparator U4A is connected to the second switch circuit.

[0034] The first switch circuit includes a capacitor C26, a resistor R30, a resistor R26, and a MOS transistor Q4A; the output terminal of the comparator U4B is respectively connected to the first end of the capacitor C26, the first end of the resistor R30, and the G pole of the MOS transistor Q4A; the second ends of the capacitor C26 and the resistor R30 are both grounded; the S pole of the MOS transistor Q4A is grounded; the D pole of the MOS transistor Q4A is connected to the first end of the resistor R26, the second end of the resistor R26 is connected to an external power supply, and the D pole of the MOS transistor Q4A is connected to the system output terminal of the hardware power supply protection system.

[0035] The second switch circuit includes a capacitor C28, a resistor R34, and a MOS transistor Q4B; the output terminal of the comparator U4A is respectively connected to the first end of the capacitor C28, the first end of the resistor R34, and the G pole of the MOS transistor Q4B; the second ends of the capacitor C28 and the resistor R34 are both grounded; the S pole of the MOS transistor Q4B is grounded; the D pole of the MOS transistor Q4B is connected to the system output terminal of the hardware power supply protection system.

[0036] Specifically, the operations of the foregoing each module circuit are described as follows:

[0037] Setting of the comparison voltage of the comparison voltage module:

[0038] Vref = 1V8_VCC × R159 / (R159 + R29)

[0039] In this embodiment, Vref is set to 0.9V, that is, both the non-inverting input terminal of the comparator U4B and the inverting input terminal of the comparator U4A are 0.9V.

[0040] Assume that the reasonable range of the system power supply input is (Vin-, Vin+), then by configuring R31 and R28, it is made that:

[0041] (Vin-) × R31 / (R28 + R31) = 0.9

[0042] That is, when it is the lowest value of the reasonable range of the power supply input, the voltage at the inverting input terminal of the comparator U4B is 0.9V. According to the formula, it can be obtained that if the actual input low value is greater than Vin-, the voltage at the inverting input terminal of the comparator U4B must be greater than 0.9V. At this time, the voltage at the non-inverting input terminal of the comparator U4B is less than the voltage at the inverting input terminal. The comparator U4B outputs a low level to the MOS transistor Q4A, and the MOS transistor Q4A is not turned on, outputting a high level, and the high level controls the normal operation of the subsequent circuit; conversely, if the actual input is less than the lowest value Vin- of the reasonable range set by the system, the MOS transistor Q4A is turned on, the output is pulled low, and the subsequent system circuit does not work.

[0043] Then, by configuring R32 and R33, it is made that:

[0044] (Vin+) × R33 / (R32 + R33) = 0.9

[0045] That is, when it is the highest value of the reasonable range of the power supply input, the voltage at the non-inverting input terminal of the comparator U4A is 0.9V; according to the formula, it can be obtained that if the actual input high value is less than Vin+, the voltage at the non-inverting input terminal of the comparator U4A is less than 0.9V. At this time, the voltage at the non-inverting input terminal of the comparator U4B is less than the voltage at the inverting input terminal. The comparator U4A outputs a low level to the MOS transistor Q4B, and the MOS transistor Q4B is not turned on, outputting a high level, and the high level controls the normal operation of the subsequent circuit; conversely, if the actual input is greater than the lowest value Vin+ of the reasonable range set by the system, the MOS transistor Q4B is turned on, the output is pulled low, and the subsequent system circuit does not work.

[0046] Therefore, when the actual power supply input range is within the preset reasonable range (Vin-, Vin+), both the comparator U4B and U4A output low levels. As the control pins of the MOS transistors, the power supply outputs normally; conversely, the comparator U4B and U4A output high levels, the MOS transistors are turned on, the output is pulled low, and the subsequent system circuit does not work.

[0047] The above technical features constitute the best embodiment of the present invention, which has strong adaptability and the best implementation effect. Non-essential technical features can be increased or decreased according to actual needs to meet the needs of different situations.

[0048] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than a limitation on the protection scope of the present invention. Any simple modification or equivalent replacement made by those of ordinary skill in the art to the technical solution of the present invention does not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A hardware power protection system based on a comparator, characterized in that: It includes a monitored power supply, a first comparison module, a second comparison module, a comparison voltage module and a switch circuit module; the first comparison module includes a comparator U4B, and the second comparison module includes a comparator U4A; The monitored power supply is respectively connected to the inverting input terminal of the comparator U4B and the non-inverting input terminal of the comparator U4A, and the non-inverting input terminal of the comparator U4B and the inverting input terminal of the comparator U4A are respectively connected to the comparison voltage module; The switch circuit module includes a first switch circuit and a second switch circuit. The output end of the comparator U4B is connected to the first switch circuit, and the output end of the comparator U4A is connected to the second switch circuit.

2. The hardware power protection system based on comparator according to claim 1, characterized in that: The first comparison module also includes a resistor R28, a resistor R31 and a capacitor C137; the first end of the resistor R28 is connected to the monitored power supply, the second end of the resistor R28 is connected to the first end of the resistor R31, and the second end of the resistor R31 is grounded; the capacitor C137 is connected in parallel to both ends of the resistor R31; the reverse input end of the comparator U4B is connected between the capacitor C137 and the second end of the resistor R28.

3. The hardware power protection system based on comparator according to claim 2, characterized in that: The second comparison module also includes a resistor R32, a resistor R33 and a capacitor C139; the first end of the resistor R32 is connected to the monitored power supply, the second end of the resistor R32 is connected to the first end of the resistor R33, and the second end of the resistor R33 is grounded; the capacitor C139 is connected in parallel at both ends of the resistor R33, and the same-direction input end of the comparator U4A is connected between the capacitor C139 and the second end of the resistor R32.

4. The hardware power protection system based on comparator according to claim 3 is characterized in that: The second comparison module also includes a resistor R35 and a capacitor C29; the first end of the resistor R35 is connected to the positive power input terminal of the comparator U4B, and the second end of the resistor R35 is connected to the external mainboard circuit; the first end of the capacitor C29 is connected to the positive power input terminal of the comparator U4B, and the second end of the capacitor C29 is grounded; the negative power input terminal of the comparator U4B is grounded.

5. The hardware power protection system based on comparator according to claim 4, characterized in that: The comparison voltage module includes a constant voltage power supply 1V8_VCC, a resistor R29, a resistor R159 and a capacitor C27; the first end of the resistor R29 is connected to the constant voltage power supply 1V8_VCC, the second end of the resistor R29 is connected to the first end of the resistor R159, and the second end of the resistor R159 is grounded; the second end of the resistor R159 is connected to the first end of the capacitor C27, and the second end of the capacitor C27 is connected to the second end of the resistor R29; The second end of the capacitor C27 is connected to the non-inverting input end of the comparator U4B and the inverting input end of the comparator U4A respectively.

6. The hardware power protection system based on comparator according to claim 1, characterized in that: The first switch circuit includes a capacitor C26, a resistor R30, a resistor R26 and a MOS tube Q4A; the output end of the comparator U4B is respectively connected to the first end of the capacitor C26, the first end of the resistor R30 and the G pole of the MOS tube Q4A; the second end of the capacitor C26 and the second end of the resistor R30 are both grounded; the S pole of the MOS tube Q4A is grounded; the D pole of the MOS tube Q4A is connected to the first end of the resistor R26, the second end of the resistor R26 is connected to the external power supply, and the D pole of the MOS tube Q4A is connected to the system output end of the hardware power protection system.

7. The hardware power protection system based on comparator according to claim 1, characterized in that: The second switch circuit includes a capacitor C28, a resistor R34 and a MOS tube Q4B; the output end of the comparator U4A is respectively connected to the first end of the capacitor C28, the first end of the resistor R34 and the G pole of the MOS tube Q4B; the second end of the capacitor C28 and the second end of the resistor R34 are both grounded; the S pole of the MOS tube Q4B is grounded; and the D pole of the MOS tube Q4B is connected to the system output end of the hardware power protection system.

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