Key wake-up circuit for electric power acquisition terminal

Abstract

The utility model relates to a key wake-up circuit for an electric power acquisition terminal, which comprises a key circuit, a wake-up circuit, a booster circuit and a slow start circuit which are connected in sequence. Wherein the key circuit is used for generating a starting signal, the wake-up circuit receives the starting signal and conducts the starting signal, a battery is connected with the booster circuit, the booster circuit is used for adjusting the voltage of the battery, and the slow starting circuit is used for guaranteeing normal starting of the circuit. According to the invention, a set of circuit is shared to realize the functions of key awakening and battery discharge control, so that the whole circuit is simpler, unnecessary components and complex connection are reduced, and the design cost is reduced; meanwhile, the circuit is designed in details to reduce energy consumption, the standby power time of the standby power source is prolonged, more durable and reliable assemblies are adopted, the working stress of key elements is reduced, and the service life of the circuit is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to power terminal wake -up technical field, concretely relates to a button wake -up circuit for power collection terminal. BACKGROUND

[0002] With the wide application of power collection terminal, the button wake -up function has become one of the basic functions of these devices. Usually, when there is no external power supply or the device is in the sleep state, the button wake -up mechanism can use the backup power supply to provide necessary power support for the whole terminal. However, the button wake -up scheme in the prior art has some significant problems: first, the circuit design is relatively complex, unnecessary design cost is increased; second, when the load is large, the performance of the existing scheme is unstable, which directly affects the normal operation of the terminal; in addition, since part of the components bear high electrical stress in the working process, they are easy to be damaged, resulting in low circuit reliability and short service life; in addition, for the case of using backup power supply, the existing scheme does not effectively consider the power consumption problem, resulting in the reduction of the standby time of the backup power supply. SUMMARY

[0003] In order to solve the above problems, the utility model provides a button wake -up circuit for power collection terminal, which comprises a button circuit, a wake -up circuit, a boost circuit and a slow start circuit, the button circuit, the wake -up circuit, the boost circuit and the slow start circuit are connected in sequence; wherein the button circuit is used for generating a start signal, the wake -up circuit receives the start signal and turns on, connects the battery to the boost circuit, the boost circuit is used for adjusting the battery voltage, and the slow start circuit is used for ensuring the normal start of the circuit.

[0004] On the basis of the above scheme, the button circuit comprises a button, the button is pressed when the terminal is running, and the button is used for returning function of the liquid crystal screen, the button is pressed when the terminal is turned off, and the button is used for wake -up and sending start signal.

[0005] On the basis of the above scheme, the button circuit further comprises a double diode, a first resistor and a first capacitor, one end of the button is grounded, the other end is connected to the cathode of the first double diode and is connected in parallel with the first capacitor, the first anode of the first double diode is connected to the first resistor, and the second anode is connected to the wake -up circuit.

[0006] On the basis of the above scheme, the wake -up circuit comprises a rechargeable battery, a second resistor, a first triode, a first MOS tube and a first diode, the battery power supply outputs a first power supply through a second capacitor, the first power supply is connected to a second power supply through a first MOS tube, and the second power supply is connected to the boost circuit.

[0007] On the basis of the above scheme, the wake-up circuit further comprises a soft start circuit and a battery discharge control circuit, the soft start circuit is used for ensuring slow opening of the second power supply, and the battery discharge control circuit is connected with the terminal and used for providing power supply for the terminal.

[0008] On the basis of the above scheme, the battery discharge control circuit comprises a third resistor, a fourth resistor and a second triode, the third resistor is connected with the first MOS tube, and the emitter of the second triode is connected with the terminal.

[0009] On the basis of the above scheme, the boost circuit comprises a boost chip, the second power supply is connected with an EN pin of the boost chip, a VS pin of the boost chip is connected with a fifth resistor and a sixth resistor and then grounded in one way, and the third power supply is output in one way, the third power supply is further connected with one end of a third capacitor and a fourth capacitor in parallel, and the other end of the third capacitor and the fourth capacitor is grounded.

[0010] On the basis of the above scheme, the boost circuit further comprises a seventh resistor, one end of the seventh resistor is connected with the VS pin of the boost chip, and the other end of the seventh resistor is connected with the EN pin.

[0011] On the basis of the above scheme, the soft start circuit comprises a second MOS tube, an eighth resistor, a ninth resistor and a second double diode, the eighth resistor, the ninth resistor and the second MOS tube are connected in parallel, and the third power supply is connected with the eighth resistor and then connected with the main power supply through the second double diode.

[0012] On the basis of the above scheme, the voltage of the third power supply is lower than that of the main power supply.

[0013] Compared with the prior art, the utility model has the advantages that:

[0014] The key circuit is connected with the wake-up circuit, when the key is pressed, a starting signal is sent, the wake-up circuit is controlled to control the switch to be turned on, the battery is further made to supply power to the whole terminal through the boost circuit, and the device is protected through the soft start circuit; a set of circuit is used to realize the key wake-up and the battery discharge control function, so that the overall circuit is more simple, unnecessary components and complex connections are reduced, and the design cost is reduced; meanwhile, the circuit is designed in details to reduce energy consumption, the standby time of the backup power supply is increased, more durable and reliable components are adopted, the working stress of the key components is reduced, and the service life of the circuit is prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a circuit composition schematic view of the utility model;

[0016] Figure 2 It is a key circuit structure schematic view of the utility model;

[0017] Figure 3 Figure 1 is a first part structure schematic diagram of the wake-up circuit of the utility model;

[0018] Figure 4 Figure 2 is a second part structure schematic diagram of the wake-up circuit of the utility model;

[0019] Figure 5 Figure 3 is a boost circuit structure schematic diagram of the utility model;

[0020] Figure 6 Figure 4 is a slow start circuit structure schematic diagram of the utility model. DETAILED DESCRIPTION

[0021] The utility model will be further described below in combination with the drawings:

[0022] In the utility model, unless another explicit provision and limitation, the terms "mount", "connect", "connect", "fix" and other terms should be broad sense, for example, can be fixed connection, or can be detachable connection, or integrated; can be directly connected, or indirectly connected through the intermediate medium, can be two elements inside the communication or the interaction relationship of two elements. For ordinary skilled in the art, the above-mentioned terms can be understood according to the specific meaning of the utility model.

[0023] The existing power collection terminal key wake-up circuit has defects such as complex circuit, high cost, poor load capacity and low performance reliability, the application provides a simple and reliable circuit, saves cost, can realize multiplexing function for a kind of circuit, realizes terminal no electricity starting function, and makes discharge time longer.

[0024] As shown in Figure 1 The key wake-up circuit of the application includes key circuit, wake-up circuit, boost circuit and slow start circuit, and the key circuit, wake-up circuit, boost circuit and slow start circuit are connected in sequence.

[0025] As shown in Figure 2 The application provides a kind of key circuit, and key circuit includes key K1, when terminal runs, the key K1 is pressed, key wake-up has no effect, can only play the function of return, i.e. KEY_ESC connects controller, realizes the return function of liquid crystal screen;When terminal is closed, the key is pressed, key wake-up, sends start signal, and passes to wake-up circuit.Specifically, the key circuit further includes double diode DB1, first resistance R1 and first capacitor C1, one end of the key K1 is grounded, the other end is connected to the cathode of first double diode, and is connected in parallel with the first capacitor, the first anode of the first double diode is connected to the first resistance, and the second anode is connected to the wake-up circuit.

[0026] Further, the first double diode is composed of two parallel Schottky diodes, which have fast switching characteristics and very short reverse recovery time, and can ensure the correctness and stability of the signal in the key circuit.

[0027] The first capacitor is a filter capacitor, which can eliminate the electrical noise that may be generated in the moment of pressing the key and ensure the stability of the signal; the first resistor R1 is a pull-up resistor, which ensures that the KEY_START signal line maintains a high level state when the key is not pressed, and becomes low when the key is pressed by grounding.

[0028] Since the battery can store energy for a long time, the backup power source used when the key is woken up is a rechargeable battery, as shown in Figure 3 and Figure 4 The wake-up circuit includes two parts: one part is that the rechargeable battery BAT1 outputs the first power supply VSBAT through the second capacitor C2, and the other part of the circuit includes the second resistor R6, the first transistor Q3, the first MOS tube Q1 and the first diode D1. When the key K1 is not pressed, VSBAT-R6-Q3-D1 does not form a complete loop, KEY_START is clamped to a high level, and the first transistor Q3 is not turned on. When the key K1 is pressed to send a low-level signal, Q3 is turned on, the first MOS tube Q1 is turned on, the first power supply VSBAT is connected to the second power supply BAT through the first MOS tube, and the second power supply BAT is connected to the boost circuit.

[0029] Specifically, the second capacitor C2 is a filter capacitor, which can stabilize the output voltage of the rechargeable battery BAT1 and reduce fluctuations.

[0030] Further, the wake-up circuit further includes a soft start circuit and a battery discharge control circuit, the fifth capacitor C3 and the tenth resistor R4 constitute the soft start circuit, which ensures that the power supply is slowly turned on, limits the current rise rate when Q1 is turned on, and protects the circuit components from surge current damage; the battery discharge control circuit is connected to the terminal, which is used to control the discharge process of the backup battery when power failure is detected.

[0031] The battery discharge control circuit includes a third resistor R3, a fourth resistor R5 and a second transistor Q2, the third resistor is connected to the first MOS tube Q1, the base of the second transistor is connected to the fourth resistor, and the signal state BAT_DCHARGE of the emitter of the second transistor is controlled by the terminal.

[0032] In this embodiment, Q1 acts as a switching role and is turned on when receiving a wake-up signal (KEY_START becomes low), allowing the battery voltage to flow to the subsequent circuit, and Q2 participates in the battery discharge control circuit to ensure that the first MOS tube Q1 continues to conduct in the case of power failure.

[0033] In this embodiment, the path of large current uses MOS tube, avoiding the use of triode, further reducing the loss; the key wake-up is actually the discharge control of the battery, sharing a set of circuit, more cost saving.

[0034] After the first MOS tube Q1 in the wake-up circuit is turned on, the second power supply BAT is connected to the EN pin of the boost chip U1, as shown in Figure 5 The VS pin of the boost chip U1 is connected to the fifth resistor R9 and the sixth resistor R10 and then grounded in one way, and outputs the third power supply BAT_POWER in one way. The third power supply is also connected to one end of the third capacitor E1 and the fourth capacitor C6 in parallel, and the other end of the third capacitor and the fourth capacitor is grounded.

[0035] U1 is responsible for converting lower voltage to higher voltage suitable for system operation, and the output voltage is adjusted according to the voltage division network composed of the fifth resistor R9 and the sixth resistor R10. The third capacitor E1 is an electrolytic capacitor, and the fourth capacitor C6 is a filter capacitor, which can further smooth the output voltage, reduce the ripple, and ensure the power supply quality. The boost circuit also includes a sixth capacitor C8, which is a feedforward capacitor, which helps to improve the output voltage regulation accuracy of the boost chip under rapidly changing load conditions, so that the boost chip can respond more accurately to load changes.

[0036] In order to increase the use time of the battery and make the battery discharge to a lower level, the boost circuit also includes a seventh resistor R7, one end of which is connected to the VS pin of the boost chip, and the other end is connected to the EN pin.

[0037] In actual work, after Q1 is turned on, BAT is connected to the boost chip U1 and enabled, and the boost chip U1 outputs a specified voltage according to the ratio of R9 and R10. After filtering, the output voltage BAT_POWER is supplied to the terminal for use. It should be noted that the output voltage BAT_POWER here needs to be lower than the main power M_POWER of the terminal when the terminal is powered by strong electricity, in order to avoid the problem that the power failure detection circuit cannot correctly identify the power failure situation.

[0038] In order to avoid the instantaneous load of the battery standby power being too large, the battery is pulled to death and cannot be started normally, a slow start circuit is added, as shown in Figure 6 The slow start circuit includes a second MOS tube Q4, an eighth resistor R11, a ninth resistor R12 and a second double diode. R11, R12 and Q4 are connected in parallel. The third power supply BAT_POWER is connected to the eighth resistor R11 and then connected to the main power supply M_POWER through the second double diode. After the MOS tube Q4 is normally started, BAT_POWER is powered through the second MOS tube Q4.

[0039] In the initial stage of starting, the BAT_POWER first provides the terminal with an initial power supply through R11 and R12 to limit the current and protect the battery from the instantaneous high load. The second MOS tube serves as a switching element and gradually connects the BAT_POWER to the main power supply line according to the control of the soft start circuit, avoiding the instantaneous current impact caused by direct loading. When the MOS tube Q4 is fully turned on, the BAT_POWER can be directly supplied to the terminal and is no longer limited by the current limiting effect of R11 and R12.

[0040] In order to match the requirements of power failure detection time and standby power time, the size of the seventh capacitor C9 can be adjusted, and the seventh capacitor C9 and the eleventh resistor R13 are combined to form a delay circuit for controlling the conduction speed of Q4. Throughout the process, the Schottky diodes D3 and D4 ensure that there is no reverse current effect on the battery discharge circuit even when the terminal switches back to the main power supply. At the same time, the use of diodes in parallel reduces the voltage drop and improves the overall efficiency.

[0041] The circuit of the present application also includes a terminal power supply, which is used to change the potential state in the circuit to high level in the circuit design, to ensure that the uncertain state on the signal line is pulled high, and to ensure that the function of the circuit is realized.

[0042] According to the present application, when the system is in a sleep or power failure state, the user presses the key K1 to issue a wake-up request, and the KEY_START signal becomes low. This signal triggers the first MOS tube Q1 in the wake-up circuit to conduct, allowing the battery voltage VSBAT to flow to the boost circuit. In the boost circuit, the boost chip U1 raises the battery voltage to the required output voltage BAT_POWER, and the voltage is stably supplied to the terminal to realize the smooth wake-up and start of the system.

[0043] When the key K1 is released, the terminal detects a strong power failure, and the control signal BAT_DCHARGE becomes low, allowing the transistor Q2 to conduct. Since the transistor Q2 is conducting, the MOS tube Q1 meets the conduction condition, allowing the battery voltage VSBAT to flow to the boost circuit. The boost chip U1 in the boost circuit adjusts and outputs the voltage BAT_POWER as the second power supply to supply the terminal, switches to the standby power supply and resumes normal operation.

[0044] The basic principle and main features of the present application are shown and described above. For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, therefore the embodiments should be regarded as exemplary and non-limiting, the scope of the present application is defined by the appended claims rather than the above description, therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application.

[0045] Furthermore, it should be understood that although the specification is described in terms of embodiments, not every embodiment includes every feature or implementation described herein. The specification can include implicit combinations of explicitly mentioned features and / or implicit combinations of implicitly mentioned features. Such combinations are also expressly included within the scope of the specification and an embodiment.

Claims

1. A key wake-up circuit for a power harvesting terminal, characterized in that, The key circuit, the wake-up circuit, the voltage boosting circuit and the slow start circuit are connected in sequence; the key circuit is used to generate a start signal; the wake-up circuit receives the start signal and turns on, and connects the battery to the voltage boosting circuit; the voltage boosting circuit is used to adjust the voltage of the battery; and the slow start circuit is used to ensure the normal start of the circuit. The wake-up circuit comprises a rechargeable battery and a first MOS tube; the rechargeable battery outputs a first power supply; the first power supply outputs a second power supply through the first MOS tube; the second power supply is connected to the voltage boosting circuit; and the voltage boosting circuit outputs a voltage to the terminal through the slow start circuit.

2. The key wake-up circuit for power harvesting terminal according to claim 1, wherein, The key circuit comprises a key; when the terminal is running, the key is pressed to return the function of the liquid crystal screen; and when the terminal is turned off, the key is pressed to wake up and send a start signal.

3. The key wake-up circuit for power harvesting terminal according to claim 2, wherein, The key circuit further comprises a double diode, a first resistor and a first capacitor; one end of the key is grounded, and the other end is connected to the cathode of the first double diode and is connected in parallel with the first capacitor; the first anode of the first double diode is connected to the first resistor; and the second anode of the first double diode is connected to the wake-up circuit.

4. The key wake-up circuit for power harvesting terminal according to claim 1, wherein, The wake-up circuit further comprises a second resistor, a second capacitor, a first triode and a first diode; the rechargeable battery outputs the first power supply through the second capacitor; the cathode of the first diode is connected to the key circuit; the anode of the first diode is connected to the emitter of the first triode; the base of the first triode is connected to the first power supply through the second resistor; and the collector of the first triode is connected to the first MOS tube.

5. The key wake-up circuit for power harvesting terminal according to claim 4, wherein, The wake-up circuit further comprises a soft start circuit and a battery discharge control circuit; the soft start circuit is used to ensure the slow opening of the second power supply; and the battery discharge control circuit is connected to the terminal and is used to control the discharge process of the backup battery when detecting power failure.

6. The key wake-up circuit for a power-harvesting terminal of claim 5, wherein, The battery discharge control circuit comprises a third resistor, a fourth resistor and a second triode; the third resistor is connected to the first MOS tube; the base of the second triode is connected to the fourth resistor; and the signal state of the emitter of the second triode is controlled by the terminal.

7. The key wake-up circuit for power harvesting terminal according to claim 4, wherein, The voltage boosting circuit comprises a voltage boosting chip; the second power supply is connected to the EN pin of the voltage boosting chip; one way of the VS pin of the voltage boosting chip is connected to the fifth resistor and the sixth resistor and then grounded; and the other way outputs a third power supply; the third power supply is further connected to one end of the third capacitor and the fourth capacitor which are connected in parallel; and the other end of the third capacitor and the fourth capacitor is grounded.

8. The key wake-up circuit for a power-harvesting terminal of claim 7, wherein, The voltage boosting circuit further comprises a seventh resistor; one end of the seventh resistor is connected to the VS pin of the voltage boosting chip; and the other end of the seventh resistor is connected to the EN pin.

9. The key wake-up circuit for power harvesting terminal according to claim 7, wherein, The slow start circuit comprises a second MOS tube, an eighth resistor, a ninth resistor and a second double diode; the eighth resistor, the ninth resistor and the second MOS tube are connected in parallel; the third power supply is connected to the eighth resistor and then connected to the main power supply through the second double diode.

10. The key wake-up circuit for a power-harvesting terminal of claim 9, wherein, The voltage of the third power supply is lower than that of the main power supply.

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