Control system for residual voltage during rapid power-on and power-off of terminal equipment

Abstract

The utility model discloses a control system for residual voltage during rapid power-on and power-off of terminal equipment, which comprises a power supply module, an MCU (Microprogrammed Control Unit) main control module, a power switch control circuit, a residual voltage processing circuit, an anti-backflow circuit and a communication module, and is characterized in that the MCU main control module is respectively connected with the power switch control circuit and the residual voltage processing circuit; the power switch control circuit is respectively connected with the power supply module and the anti-backflow circuit, and the communication module is respectively connected with the anti-backflow circuit and the residual voltage processing circuit. According to the utility model, the communication module can be prevented from working abnormally and being damaged permanently under the conditions that the terminal equipment is powered off in an abnormal condition and the communication module needs to be switched on and off repeatedly, and the reliability of long-term communication work of the low-power-consumption terminal equipment is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply control circuits, and in particular to a control system for residual voltage when terminal equipment is powered on and off quickly. Background Art

[0002] Nowadays, many IoT terminal devices include MCU main control module and communication module. The existing communication module power control design only focuses on the power-on control, but does not pay attention to the processing of the residual voltage after the communication module enters the low-power mode. Because with the rise of IoT devices and the low power demand being valued by customers, designers need to consider the power consumption and working stability of the communication module when switching between various working modes.

[0003] When the terminal device is operating normally, it is necessary to supply power to the communication module so that the communication module can operate in initialization, transceiver mode and deep sleep mode; when the terminal device is in sleep mode, the power supply is cut off. If the load circuit has a large capacitor, the voltage on the load circuit of the communication module will drop slowly, causing the residual voltage on the IO port of the communication module to be fed back to the MCU main control module. At present, many low-power IoT terminal devices need to switch between multiple working modes. Since the communication module needs to switch from the heavy load in the normal transceiver mode to the light load in the sleep mode, the traditional design does not consider the scenario where the terminal device encounters special situations (such as detecting a short circuit or other situations) and needs to quickly and repeatedly switch the communication module. If the load circuit is powered on again without completely losing power, it may cause abnormal power failure, failure to initialize the communication module during rapid switching, memory data loss, abnormal operation of the communication module, or startup crash. Utility Model Content

[0004] In view of this, the purpose of the utility model is to provide a control system for residual voltage when terminal equipment is quickly powered on and off.

[0005] In order to achieve the above-mentioned technical objectives, the technical solution adopted by the utility model is: a control system for the residual voltage when the terminal equipment is quickly powered on and off, including: a power supply module, an MCU main control module, a power switch control circuit, a residual voltage processing circuit, an anti-backflow circuit and a communication module, the MCU main control module is respectively connected to the power switch control circuit and the residual voltage processing circuit, the power switch control circuit is respectively connected to the power supply module and the anti-backflow circuit, and the communication module is respectively connected to the anti-backflow circuit and the residual voltage processing circuit.

[0006] Furthermore, the power switch control circuit includes a diode D2, a resistor R1, a resistor R2, a resistor R4, a resistor R5, a capacitor C1, a transistor Q2 and a MOS tube Q1, the cathode of the diode D2 and one end of the resistor R4 are both connected to the MCU main control module, the B pole of the transistor Q2 is respectively connected to the anode of the diode D2, the other end of the resistor R4 and one end of the resistor R5, the E pole of Q2 and the other end of the resistor R5 are grounded, the C pole of the transistor Q2 is connected to one end of the resistor R2, the G pole of the MOS tube Q1 is respectively connected to the other end of the resistor R2, one end of the capacitor C1 and one end of the resistor R1, the S pole of the MOS tube Q1, the other end of the capacitor C1 and the other end of the resistor R1 are all connected to the power supply module, and the D pole of the MOS tube Q1 is connected to the anti-backflow circuit.

[0007] Furthermore, the residual voltage processing circuit includes a resistor R3, a resistor R6, a capacitor C3 and a transistor Q3, one end of the resistor R3 and one end of the capacitor C3 are both connected to the MCU main control module, the B pole of the transistor Q3 is respectively connected to the other end of the resistor R3 and the other end of the capacitor C3, the C pole of the transistor Q3 is connected to one end of the resistor R6, and the other end of the resistor R6 is grounded; the E pole of the transistor Q3 is connected to the communication module.

[0008] Furthermore, the residual voltage processing circuit also includes a capacitor C2, one end of the capacitor C2 is grounded, and the other end of the capacitor C2 is connected to the E pole of the transistor Q3.

[0009] Furthermore, the anti-backflow circuit includes a diode D1, the anode of the diode D1 is connected to the D pole of the MOS tube Q1, and the cathode of the diode D1 is connected to the communication module.

[0010] Furthermore, the cathode of the diode D2, one end of the resistor R4, one end of the resistor R3 and one end of the capacitor C3 are all connected to the same IO port of the MCU main control module.

[0011] Furthermore, the MOS tube Q1 is a PMOS tube.

[0012] Furthermore, the transistor Q2 is an NPN transistor, and the transistor Q3 is a PNP transistor.

[0013] Furthermore, the diode D1 and the diode D2 are Schottky diodes.

[0014] By adopting the above technical solution, the utility model has the following beneficial effects compared with the prior art:

[0015] 1. The utility model adopts an anti-backflow circuit. When the terminal device is in sleep mode, the power supply is cut off. If the load circuit has a large capacitor, the residual voltage of the IO port of the communication module can be prevented from backflowing to the MCU main control module, thereby ensuring the normal operation of the system;

[0016] 2. The utility model adopts the same control signal source (the same IO port output control signal of the MCU main control module) to utilize the interlock switch and finely control the switching action time sequence between the power switch control circuit and the residual voltage processing circuit, introduces dead time, avoids the situation where the two circuits are opened or closed at the same time, which causes excess power loss, reduces the operating power consumption, and can meet the situation that the terminal equipment is powered off under abnormal circumstances and the communication module needs to be repeatedly switched on and off. The communication module will not have abnormal operation and permanent damage, etc., thereby ensuring the reliability of long-term communication work of low-power terminal equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a structural block diagram of a control system for residual voltage when a terminal device is quickly powered on and off, provided by an embodiment of the utility model.

[0019] Figure 2 It is a specific structural schematic diagram of a power switch control circuit and a residual voltage processing circuit provided in an embodiment of the utility model.

[0020] Figure 3 It is a flowchart of the power-on process provided by an embodiment of the utility model.

[0021] Figure 4 It is a flowchart of the power-off process provided by an embodiment of the utility model.

[0022] Description of the numbers in the figure:

[0023] 1-power supply module, 2-MCU main control module, 3-power switch control circuit, 4-residual voltage processing circuit, 5-anti-backflow circuit, 6-communication module. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is particularly noted that the following embodiments are only used to illustrate the present invention, but do not limit the scope of the present invention. Similarly, the following embodiments are only partial embodiments of the present invention rather than all embodiments. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] See also Figure 1 and Figure 2 The utility model discloses a control system for residual voltage when a terminal device is powered on and off quickly, comprising: a power supply module 1, an MCU main control module 2, a power switch control circuit 3, a residual voltage processing circuit 4, an anti-backflow circuit 5 and a communication module 6, wherein the MCU main control module 2 is respectively connected to the power switch control circuit 3 and the residual voltage processing circuit 4, the power switch control circuit 3 is respectively connected to the power supply module 1 and the anti-backflow circuit 5, and the communication module 6 is respectively connected to the anti-backflow circuit 5 and the residual voltage processing circuit 4.

[0026] In this embodiment, the power switch control circuit 3 includes a diode D2, a resistor R1, a resistor R2, a resistor R4, a resistor R5, a capacitor C1, a transistor Q2 and a MOS transistor Q1. The cathode of the diode D2 and one end of the resistor R4 are both connected to the MCU main control module 2. The B pole of the transistor Q2 is respectively connected to the anode of the diode D2, the other end of the resistor R4 and one end of the resistor R5. The E pole of Q2 and the other end of the resistor R5 are grounded. The C pole of the transistor Q2 is connected to one end of the resistor R2. The G pole of the MOS tube Q1 is respectively connected to the other end of the resistor R2, one end of the capacitor C1 and one end of the resistor R1. The S pole of the MOS tube Q1, the other end of the capacitor C1 and the other end of the resistor R1 are all connected to the power supply module 1. The D pole of the MOS tube Q1 is connected to the anti-backflow circuit 5. The MCU main control module 2 outputs a high level of the control signal to drive the NPN transistor Q2 to turn on and a low level to drive the fast shutdown, thereby increasing the driving capability to control the on and off of the high-power PMOS tube Q1 to indirectly control the on and off of the power supply of the communication module 6. The Schottky diode D2 is used to quickly pull down the B pole of the NPN transistor Q2 when the control signal is at a low level, so that the NPN transistor Q2 is quickly turned off, thereby allowing the PMOS tube Q1 to also achieve a fast shutdown; the resistor R2 and the capacitor C1 form an RC charging delay; the resistor R1 is an energy-consuming resistor of the capacitor C1 discharge circuit, which plays a role in fast shutdown; the resistor R4 is a current-limiting resistor, which also plays a delay role; the resistor R5 is a pull-down resistor, which plays an anti-interference role.

[0027] In this embodiment, the residual voltage processing circuit 4 includes a resistor R3, a resistor R6, a capacitor C2, a capacitor C3 and a transistor Q3, one end of the resistor R3 and one end of the capacitor C3 are both connected to the MCU main control module 2, the B pole of the transistor Q3 is respectively connected to the other end of the resistor R3 and the other end of the capacitor C3, the C pole of the transistor Q3 is connected to one end of the resistor R6, and the other end of the resistor R6 is grounded; the E pole of the transistor Q3 is respectively connected to the communication module 6 and one end of the capacitor C2, and the other end of the capacitor C2 is grounded. The high level of the control signal output by the same IO port of the MCU main control module 2 drives the PNP transistor Q3 to turn off quickly and the low level to drive it to turn on slowly; the Schottky diode D1 is used to prevent the current of the large capacitor at the back end of the communication module 6 from being fed back to the input power supply when the PMOS tube Q1 is turned off, causing other abnormal problems; the capacitor C3 is used to accelerate the opening and delay the shutdown of the PNP transistor Q3; the resistor R3 is a current limiting resistor, which also plays a delay role; the capacitor C2 is a large-capacity filter capacitor of the communication module 6 to prevent the voltage drop and other phenomena caused by insufficient load capacity during transmission and reception; the resistor R6 is a residual voltage discharge resistor, which is used to quickly reduce the power consumption of the residual voltage. The resistance value of the resistor R6 can be adjusted according to the switching requirements of the terminal equipment to meet the performance requirements.

[0028] In this embodiment, the anti-backflow circuit 5 includes a diode D1, the positive electrode of the diode D1 is connected to the D electrode of the MOS tube Q1, and the negative electrode of the diode D1 is connected to the communication module 6. The utility model adopts the anti-backflow circuit 5, when the terminal device is dormant and the power supply is cut off, if the load circuit has a large capacitor, the residual voltage of the IO port of the communication module 6 can be prevented from being backflowed to the MCU main control module 2, thereby ensuring the normal operation of the system.

[0029] In this embodiment, the cathode of the diode D2, one end of the resistor R4, one end of the resistor R3 and one end of the capacitor C3 are all connected to the same IO port of the MCU main control module 2. It can be ensured that the levels output to the power switch control circuit 3 and the residual voltage processing circuit 4 are the same, and have the same control signal source; the same control signal source is used to switch the mutually exclusive on and off of the power switch control circuit 3 and the residual voltage processing circuit 4, so as to realize the opening and closing of the two circuits.

[0030] In this embodiment, the MOS transistor Q1 is a PMOS transistor.

[0031] In this embodiment, the transistor Q2 is an NPN transistor, and the transistor Q3 is a PNP transistor, which can realize the mutual exclusive switching of the power switch control circuit 3 and the residual voltage processing circuit 4.

[0032] In this embodiment, the diode D1 and the diode D2 are Schottky diodes.

[0033] The working principle of the utility model is as follows:

[0034] The utility model uses the MCU main control module 2 to control the rapid operation and shutdown of various communication modules 6 to meet the low power consumption design requirements. The complete working process is as follows: Figure 1 and Figure 2 As shown, the MCU main control module 2 controls the power switch control circuit 3 and the residual voltage processing circuit 4 to mutually exclude each other through the high and low levels of the control signal output by the same IO port, so that the communication module 6 can achieve fast power supply operation and shutdown to avoid the scenario where the communication module 6 needs to be turned on and off quickly and there is a large-capacity capacitor on the load of the communication module 6.

[0035] A residual voltage processing circuit 4 is designed to quickly discharge the residual power of the communication module 6 so that the terminal device can operate in working scenarios such as rapid repeated switching.

[0036] Figure 2 The left virtual box is the power switch control circuit 3. The MCU main control module 2 outputs a high level of the control signal to drive the NPN transistor Q2 to turn on and a low level to drive the fast shutdown, thereby increasing the driving capability to control the on and off of the high-power PMOS tube Q1 to indirectly control the on and off of the power supply of the communication module 6. The Schottky diode D2 is used to quickly pull down the B pole of the NPN transistor Q2 when the control signal is at a low level, so that the NPN transistor Q2 is quickly turned off, thereby allowing the PMOS tube Q1 to also achieve a fast shutdown; the resistor R2 and the capacitor C1 form an RC charging delay; the resistor R1 is an energy-consuming resistor of the capacitor C1 discharge circuit, which plays a role in fast shutdown; the resistor R4 is a current-limiting resistor, which also plays a delay role; the resistor R5 is a pull-down resistor, which plays an anti-interference role.

[0037] Figure 2 The residual voltage processing circuit 4 is in the virtual box on the right. The high level of the control signal output by the same IO port of the MCU main control module 2 drives the PNP transistor Q3 to turn off quickly and the low level to drive it to turn on slowly; the Schottky diode D1 is used to prevent the current of the large capacitor at the back end of the communication module 6 from being fed back to the input power supply when the PMOS tube Q1 is turned off, causing other abnormal problems; the capacitor C3 is used to accelerate the opening and delay the shutdown of the PNP transistor Q3; the resistor R3 is a current limiting resistor, which also plays a delay role; the capacitor C2 is a large-capacity filter capacitor of the communication module 6 to prevent the voltage drop and other phenomena caused by insufficient load capacity during transmission and reception; the resistor R6 is a residual voltage discharge resistor, which is used to quickly reduce the power consumption of the residual voltage and release it. The resistance value of the resistor R6 can be adjusted according to the switching requirements of the terminal equipment to meet the performance requirements.

[0038] The whole system is designed to use the same control signal source to switch the mutually exclusive on and off of the power switch control circuit 3 and the residual voltage processing circuit 4, and at the same time, there is a time sequence between the opening and closing of the two circuits.

[0039] like Figure 3 As shown, when powered on, the power switch control circuit 3 indirectly drives the PMOS tube Q1 to turn on after the NPN transistor Q2 is turned on, and the capacitor C1 is added to the PMOS tube Q1 to perform a slow start design to reduce the voltage fluctuation at the moment of power-on; and the PNP transistor Q3 in the residual voltage processing circuit 4 is added with a capacitor C3 to achieve fast shutdown, so when powered on, the shutdown action of the residual voltage processing circuit 4 takes precedence over the opening action of the power switch control circuit 3;

[0040] like Figure 4 As shown, when the power is off, since the control signal in the power switch control circuit 3 has a reverse Schottky diode D2 loop, the PMOS tube Q1 can be quickly turned off to cut off the power output; at the same time, the residual voltage processing circuit 4 has a forward Schottky diode D1 to prevent the large capacitor voltage in the communication module 6 from being fed back to the power switch control circuit 3 to affect its shutdown and power supply end, wherein the capacitor C3 can realize the slow opening of the PNP transistor Q3, so that when the power is off, the power switch control circuit 3 shuts down and takes precedence over the residual voltage processing circuit 4 opening action. This mutually exclusive and time-sequential clever design is conducive to avoiding unnecessary switching losses and current loss in the discharge resistance loop of the residual voltage processing circuit 4, resulting in a large overall average power consumption of the low-power device. At the same time, since the residual voltage processing circuit 4 does not pass through the power supply module 1, the communication module 6 can be quickly powered on and operated when it enters the low-power mode, ensuring that the communication module 6 can operate normally and the stability of the power supply end when the terminal device is repeatedly powered on and off, greatly improving the reliability of the system circuit.

[0041] The above descriptions are only some embodiments of the present invention, and do not limit the protection scope of the present invention. Any equivalent device or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A control system for residual voltage when a terminal device is powered on or off quickly, characterized in that: include: A power supply module, an MCU main control module, a power switch control circuit, a residual voltage processing circuit, an anti-backflow circuit and a communication module, wherein the MCU main control module is respectively connected to the power switch control circuit and the residual voltage processing circuit, the power switch control circuit is respectively connected to the power supply module and the anti-backflow circuit, and the communication module is respectively connected to the anti-backflow circuit and the residual voltage processing circuit.

2. A control system for residual voltage when a terminal device is quickly powered on or off as claimed in claim 1, characterized in that: The power switch control circuit includes a diode D2, a resistor R1, a resistor R2, a resistor R4, a resistor R5, a capacitor C1, a transistor Q2 and a MOS tube Q1. The cathode of the diode D2 and one end of the resistor R4 are both connected to the MCU main control module, the B pole of the transistor Q2 is respectively connected to the anode of the diode D2, the other end of the resistor R4 and one end of the resistor R5, the E pole of Q2 and the other end of the resistor R5 are grounded, the C pole of the transistor Q2 is connected to one end of the resistor R2, the G pole of the MOS tube Q1 is respectively connected to the other end of the resistor R2, one end of the capacitor C1 and one end of the resistor R1, the S pole of the MOS tube Q1, the other end of the capacitor C1 and the other end of the resistor R1 are all connected to the power supply module, and the D pole of the MOS tube Q1 is connected to the anti-backflow circuit.

3. A control system for residual voltage when a terminal device is powered on or off quickly as claimed in claim 2, characterized in that: The residual voltage processing circuit includes a resistor R3, a resistor R6, a capacitor C3 and a transistor Q3, one end of the resistor R3 and one end of the capacitor C3 are both connected to the MCU main control module, the B pole of the transistor Q3 is respectively connected to the other end of the resistor R3 and the other end of the capacitor C3, the C pole of the transistor Q3 is connected to one end of the resistor R6, and the other end of the resistor R6 is grounded; the E pole of the transistor Q3 is connected to the communication module.

4. A control system for residual voltage when a terminal device is quickly powered on or off as claimed in claim 3, characterized in that: The residual voltage processing circuit further includes a capacitor C2, one end of the capacitor C2 is grounded, and the other end of the capacitor C2 is connected to the E pole of the transistor Q3.

5. A control system for residual voltage when a terminal device is quickly powered on or off as claimed in claim 3, characterized in that: The anti-backflow circuit includes a diode D1 , an anode of the diode D1 is connected to the D pole of the MOS tube Q1 , and a cathode of the diode D1 is connected to the communication module.

6. A control system for residual voltage when a terminal device is powered on or off quickly as claimed in claim 3, characterized in that: The cathode of the diode D2, one end of the resistor R4, one end of the resistor R3 and one end of the capacitor C3 are all connected to the same IO port of the MCU main control module.

7. A control system for residual voltage when a terminal device is powered on or off quickly as claimed in claim 2, characterized in that: The MOS tube Q1 is a PMOS tube.

8. A control system for residual voltage when a terminal device is powered on or off quickly as claimed in claim 3, characterized in that: The transistor Q2 is an NPN transistor, and the transistor Q3 is a PNP transistor.

9. A control system for residual voltage when a terminal device is powered on or off quickly as claimed in claim 5, characterized in that: The diode D1 and the diode D2 are Schottky diodes.

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