CN204496429U - Shutdown control circuit and there is the electronic product of described shutdown control circuit - Google Patents

Abstract

The utility model discloses a shutdown control circuit and an electronic product with the shutdown control circuit, which is provided with a power supply management circuit, a system main circuit, a specific function circuit that requires continuous operation when the electronic product is used and shut down, a startup button and a full shutdown button, one end of the power-on button is connected to the positive pole of the battery, and the other end is connected to the enable end of the first power conversion chip, and when the power-on button is pressed, the first power conversion chip is controlled to enable and supply power to the main circuit of the system; One end of the full shutdown button is connected to the system voltage, and the other end is connected to the system main circuit. When the system main circuit detects that the full shutdown button is pressed, it outputs a full shutdown signal to control the second power conversion chip to stop running and cut off the Power supply for specific function circuits. By designing a system-wide shutdown mode, the power consumption of the internal battery of the electronic product can be minimized, and the storage time of the electronic product in the warehouse after charging can be extended.

Description

Shutdown control circuit and electronic product with said shutdown control circuit

technical field

The utility model relates to a circuit structure design for controlling the shutdown of electronic products, in particular to a shutdown control circuit that can support two modes of shutdown of the main system and shutdown of the whole system and a design using the shutdown control circuit electronic product.

Background technique

With the advancement of technology, wearable electronic products are favored and widely used by more and more consumers, and the functions they can achieve are also increasing. Since the current wearable electronic products are generally small in size and light in weight, this determines that batteries suitable for such electronic products are generally small in size and battery capacity.

In order to enable consumers to have a direct start-up experience when they get this type of electronic product for the first time, the manufacturer will pre-charge a small amount of power to the battery inside the product before leaving the factory. Since many wearable electronic products now have the function of displaying time, in order to ensure the accuracy of timekeeping, manufacturers currently design the real-time clock chip inside the product to always maintain the power-on operation mode when designing circuits, even in electronic devices. The product is still working continuously when it is turned off, which leads to continuous power consumption of the product.

After the electronic products leave the factory, they may be stored in the warehouse for a long period of time before they reach the hands of consumers. As a result, consumers will reduce their willingness to purchase due to the inability to have a normal boot experience when purchasing.

Therefore, how to minimize the shutdown loss of wearable electronic products and ensure the lowest power consumption of the battery during the period from the factory to the consumer, even if it is stored in the warehouse for a long time, after the consumer takes it for the first time At that time, it can be guaranteed that it can be turned on normally to complete the first experience, which is a common problem faced by many electronic products powered by batteries.

Contents of the invention

The purpose of this utility model is to provide a shutdown control circuit that supports two modes of shutdown of the main system and shutdown of the whole system. By controlling the shutdown of the entire system when the electronic product leaves the factory, the power of the battery inside the electronic product can be reduced to the greatest extent. Consumption, prolong the warehouse storage time of electronic products after charging.

In order to solve the above-mentioned technical problems, the utility model adopts the following technical solutions to achieve:

A shutdown control circuit, which is used in battery-powered electronic products, in which a power management circuit, a system main circuit, and a specific function circuit that requires continuous operation when the electronic product is shut down; in the power management The circuit is provided with a first power conversion chip for supplying power to the main circuit of the system and a second power conversion chip for supplying power to the specific function circuit; a power-on button and a full shutdown button are arranged on the electronic product, and the power-on button One end is connected to the positive pole of the battery, and the other end is connected to the enable end of the first power conversion chip. When the power-on button is pressed, the first power conversion chip is controlled to be enabled, and the battery voltage is converted into the system voltage to supply power for the main circuit of the system; One end of the full shutdown button is connected to the system voltage, and the other end is connected to the system main circuit. When the system main circuit detects that the full shutdown button is pressed, it outputs a full shutdown signal to control the second power conversion chip to stop running and cut off all The power supply of the specific function circuit described above.

Further, a main control chip and a peripheral function circuit connected thereto are arranged in the main circuit of the system, and the full shutdown button is connected between the battery and the main control chip.

In order to ensure that the main control chip will not be powered off before completing the necessary work, the utility model connects an energy storage capacitor and a discharge resistor between the enabling terminal of the first power conversion chip and the system ground, and presses the When the power-on button and the full-off button are used to control the full shutdown of the electronic product in the shutdown state, the energy storage capacitor receives and stores the electric energy output by the battery during the period when the power-on button is pressed. Discharge to delay the shutdown time of the first power conversion chip, so as to reserve enough running time for the main control chip to ensure that the main control chip can complete the output of the full shutdown signal and data storage and other related work.

In order to ensure that the main circuit of the system can have continuous power supply even if the power-on button is disconnected when the control electronic product is turned on and running, the utility model connects the enable end of the first power conversion chip to the cathode of a pair of diode devices, so The cathode of the dual diode device is butted, and the two anodes are respectively connected to the power-on button and the main control chip in one-to-one correspondence; the main control chip outputs a power-on signal through the dual diode The device is transmitted to the enable terminal of the first power conversion chip, and the first power conversion chip is controlled to be continuously enabled and operated, so as to continuously supply power to the main circuit of the system.

In order to effectively control the operation of the second power conversion chip, a switch circuit is connected to the enabling terminal of the second power conversion chip, and the switch circuit operates when receiving the full shutdown signal output by the system main circuit , pull down the potential of the enabling end of the second power conversion chip, control the second power conversion chip to stop running, cut off the power supply of the specific function circuit and enter the system-wide shutdown state; state, output a high-level active enable signal to the enable terminal of the second power conversion chip, control the second power conversion chip to enable operation, and convert the battery voltage into the working voltage required by the specific function circuit , supplying power to the specific function circuit, feeding back the output working voltage to the enabling terminal of the second power conversion chip, maintaining the continuous operation of the second power conversion chip, and controlling the continuous power-on operation of the specific function circuit.

Preferably, an N-channel MOS transistor is provided in the switch circuit, the gate of the MOS transistor receives the full shutdown signal, the drain is connected to the enable terminal of the second power conversion chip, and the source is grounded.

Wherein, the enable signal output by the system main circuit is transmitted to the enable terminal of the second power conversion chip through an anti-reverse bias diode.

Preferably, the specific function circuit may be a real-time clock circuit, which is used to generate a clock signal and transmit it to the main system circuit, so that the function of displaying the real-time clock can be realized on the electronic product.

Preferably, the power-on button and the full-off button are preferably mechanical buttons without a holding function, and the full-off button is preferably installed in the housing of the electronic product, and is only used by technicians before the electronic product leaves the factory; The power-on button can be exposed to the shell of the electronic product, which can be used by technicians and ordinary users.

Based on the structural design of the above shutdown control circuit, the utility model also proposes an electronic product designed with the shutdown control circuit, the electronic product is powered by a battery; the electronic product is provided with a power management circuit, a system main circuit and a specific function circuit that requires continuous operation when the electronic product is turned off; the power management circuit is provided with a first power conversion chip that supplies power to the main circuit of the system and a second power conversion chip that supplies power to the specific function circuit ; The electronic product is provided with a power-on button and a full-off button, one end of the power-on button is connected to the positive pole of the battery, and the other end is connected to the enabling end of the first power conversion chip. When the power-on button is pressed, the first The power conversion chip is enabled, and the battery voltage is converted into a system voltage to supply power for the system main circuit; one end of the full shutdown button is connected to the system voltage, and the other end is connected to the system main circuit, and the system main circuit is When the shutdown button is pressed, a full shutdown signal is output to control the second power conversion chip to stop running, cutting off the power supply of the specific function circuit.

Compared with the prior art, the advantages and positive effects of the utility model are: the utility model designs the whole system shutdown function in the electronic product, and when the electronic product leaves the factory, it can control the electronic product to enter the whole system shutdown mode to maximize Minimize the consumption of battery power, ensure that after the electronic product is charged and leaves the factory, even if it has been stored in the warehouse for a long time, it can still be turned on and run as usual when it reaches the consumer, completing the consumer's first experience, thereby eliminating the need for The impact of the problem of not being able to turn on the machine on consumers' willingness to purchase. The shutdown control technology proposed by the utility model is especially suitable for application in wearable electronic products with small battery capacity, so as to prolong the storage time of such electronic products as much as possible.

After reading the detailed description of the embodiments of the utility model in conjunction with the accompanying drawings, other features and advantages of the utility model will become clearer.

Description of drawings

Fig. 1 is the circuit principle diagram of a kind of embodiment of system main circuit in the shutdown control circuit that the utility model proposes;

Fig. 2 is a schematic diagram of the system main power supply circuit of an embodiment of providing power supply for the system main circuit shown in Fig. 1;

Fig. 3 is a control circuit schematic diagram of an embodiment for controlling the main power supply circuit of the system shown in Fig. 2;

Fig. 4 is the circuit principle diagram of a kind of embodiment of specific function circuit in the shutdown control circuit that the utility model proposes;

FIG. 5 is a schematic diagram of a power circuit of an embodiment for providing power supply for the specific function circuit shown in FIG. 4 .

Detailed ways

Below in conjunction with accompanying drawing, the specific embodiment of the present utility model is described in further detail.

In this embodiment, the power supply circuit is designed for battery-powered electronic products, in order to minimize the consumption of battery power, prolong the storage time of such electronic products as much as possible, and ensure that consumers can start normally when purchasing such electronic products. After completing the first experience, this embodiment designs a brand-new shutdown control circuit in the electronic product. On the basis of retaining the traditional shutdown processing mode, a system-wide shutdown control mode is added. By controlling all the system circuits inside the electronic product to shut down , thereby saving power to the greatest extent.

Taking wearable electronic products as an example, the specific circuit structure and working principle of the shutdown control circuit proposed in this embodiment will be described in detail below.

In most of the current wearable electronic products, the main circuit part of the internal system is usually designed to be switched on and off by the user, and for some specific functional circuits in the system, such as the real-time clock circuit, etc., in order to To ensure the accuracy of timekeeping, even if the user performs a shutdown operation, this part of the functional circuit will not shut down, but will continue to run, resulting in continuous consumption of battery power.

Since the functions realized by this part of the specific functional circuit may not be necessary during the period from the delivery of the electronic product to the hand of the consumer, in order to prolong the storage time of the electronic product in the warehouse after leaving the factory, this embodiment proposes a This kind of design idea of controlling the shutdown of this part of the specific function circuit during the storage period of the electronic product, and the uninterrupted operation after the user uses it, and then reduces the power consumption of the product during the storage period under the premise of ensuring that the existing functions of the electronic product remain unchanged. Consumption, prolonging the inventory time of the product.

In order to achieve the above design purpose, the present embodiment designs the power-on button SW1 and the full-off button SW2 on the electronic product. As shown in Fig. The mechanical button implementation of the hold function. Wherein, the power-on button SW1 is used to control the power-on of the electronic product, and is connected between the battery inside the electronic product and the main power supply circuit of the system. Specifically, one end of the power-on button SW1 can be connected to the positive pole VBAT of the battery, and the other end can be connected to the enable terminal CE of the first power conversion chip U5 in the main power circuit of the system. The first power conversion chip U5 is used to convert the battery voltage into the working voltage required by the main circuit of the system (hereinafter referred to as the system voltage VSYS_3V0), and supply power to the main circuit of the system. Specifically, a low-dropout linear regulator LDO or DC can be selected. - The DC converter realizes the conversion of the battery voltage to the system voltage VSYS_3V0.

In this embodiment, the input terminal VDD of the first power conversion chip U5 is connected to the positive pole VBAT of the battery, and grounded through the capacitor C3, and the voltage output by the battery is filtered by the capacitor C3 to ensure the voltage input to the first power conversion chip U5 Stablize. The output terminal VOUT of the first power conversion chip U5 is connected to the main circuit of the system, and the filter capacitor C5 is designed to ensure the stability of the system voltage VSYS_3V0 provided to the main circuit of the system.

A main control chip U2 and peripheral function circuits (not shown in the figure) connected thereto are designed in the system main circuit. In this embodiment, the main control chip U2 is used as the control core of the entire system, and a single-chip microcomputer MCU or CPU can be selected. Since the power-on button SW1 does not have a hold function, when the user releases the button after pressing it, the power-on button SW1 will be disconnected immediately, thereby causing the first power conversion chip U5 to stop enabling. In order to ensure that the first power conversion chip U5 can continuously output the system voltage VSYS_3V0 when the user presses the power-on button SW1 to control the power-on of the electronic product, so as to ensure that the main circuit of the system continues to be powered on and running, this embodiment designs the main control chip U2 to enter the power-on operation mode Afterwards, an active-high power-on signal PWR_ON_CTL is output and transmitted to the enable terminal CE of the first power conversion chip U5 to control the first power conversion chip U5 to continue to enable operation.

As a preferred design method of this embodiment, a dual diode device D2 is designed in the control circuit of the main power supply of the system in this embodiment, as shown in FIG. 3 . The two cathodes of the dual diode device D2 are connected to each other, and are connected to the enabling terminal CE of the first power conversion chip U5. One of the two anodes of the dual diode device D2 is connected to the power-on button SW1, and the other is connected to the The pin of the main control chip U2 outputting the power-on signal PWR_ON_CTL, for example, one of the GPIO ports P0.10 of the main control chip U2. Utilize the reverse cut-off characteristic of the diode device to ensure that the enable signal generated by pressing the power-on button SW1 and the power-on signal PWR_ON_CTL output by the main control chip U2 can be transmitted to the enable terminal CE of the first power conversion chip U5 in the correct flow direction, The first power conversion chip U5 is controlled to continue to enable operation during the period when the electronic product is powered on.

An energy storage capacitor C4 and a discharge resistor R8 are respectively connected between the enable terminal CE of the first power conversion chip U5 and the system ground, as shown in FIG. 2 , to delay the shutdown timing of the first power conversion chip U5 . The working principle of this part of the circuit will be described in detail in the subsequent description.

The full shutdown button SW2 is used to control the entire system circuit of the electronic product to be completely closed. In this embodiment, it is connected between the output terminal VOUT of the first power conversion chip U5 and one of the GPIO ports P0.28 of the main control chip U2, such as Figure 1 shows. When the main control chip U2 detects that the full shutdown button SW2 is pressed, that is, when its GPIO port P0. Port P0.09 output) to the specific function circuit in the electronic product, and control the specific function circuit to close.

In this embodiment, the specific functional circuit is preferably described by taking the real-time clock circuit as an example, including the second power conversion chip U1 and the real-time clock chip U4 and other main components, as shown in FIG. 4 and FIG. 5 . The second power conversion chip U1 can also use a low-dropout linear regulator LDO or a DC-DC converter to convert the battery voltage into the working voltage RTC_3V0 required by the real-time clock chip U4, which is the real-time clock chip U4 powered by.

Specifically, the input terminal VDD of the second power conversion chip U1 can be connected to the positive pole VBAT of the battery, and grounded through the filter capacitor C2; the output terminal VOUT of the second power conversion chip U1 can be connected to the power supply terminal VDD of the real-time clock chip U4, And the operating voltage RTC_3V0 converted and output by the second power conversion chip U1 is filtered through the filter capacitors C1 and C7. Connect the enable end CE of the second power conversion chip U1 to its output end VOUT through a current limiting resistor R3, and connect the other end to ground through a switch path of a switch circuit, and the control end of the switch circuit is connected to the main control chip U2 receives the full shutdown signal RTC_LDO_SHUT output by the main control chip U2.

In this embodiment, the switch circuit is preferably designed by using an N-channel MOS transistor Q1 and a simple peripheral circuit, as shown in FIG. 5 . Connect the gate of the N-channel MOS transistor Q1 to the P0.09 pin of the main control chip U2, receive the full shutdown signal RTC_LDO_SHUT output by the main control chip U2, and ground through the configuration resistor R4. The source of the N-channel MOS transistor Q1 is grounded, and the drain is connected to the enable terminal CE of the second power conversion chip U1, or connected to the enable terminal CE of the second power conversion chip U1 through a resistor R5 with a small resistance value. Capable of CE. When it is necessary to control the shutdown of the real-time clock chip U4, the main control chip U2 can output a high-level active full shutdown signal RTC_LDO_SHUT, and then control the saturation conduction of the N-channel MOS transistor Q1, and pull down the enable of the second power conversion chip U1 The potential of terminal CE controls the second power conversion chip U1 to stop running, and then cuts off the power supply to the real-time clock chip U4, so as to achieve the design purpose of controlling the power-off and shutdown of the real-time clock chip U4.

Certainly, the switching circuit may also use triodes, silicon controlled rectifiers and other components with switching functions for specific design of the circuit, and this embodiment is not limited to the above example.

In addition, in order to restart the operation after the real-time clock chip U4 is turned off, this embodiment designs the main control chip U2 to output the enable signal RTC_LDO_EN (for example, through the GPIO port P0 of the main control chip U2 ) when it needs to control the real-time clock chip U4 to start. .08 output), through the anti-reverse bias diode D105 and current-limiting resistor R1 to the enable terminal CE of the second power conversion chip U1, control the second power conversion chip U1 to enable operation, and then convert the battery voltage into a real-time clock chip The working voltage RTC_3V0 required by U4 supplies power for the real-time clock chip U4. After the real-time clock chip U4 is powered on and running, it generates a clock signal, which is transmitted to the main control chip U2 through the I ² C bus SDA and SCL, and generates the current clock through the main control chip U2, which is output and displayed on the display screen of the electronic product.

The working principle of this embodiment will be described in detail below in conjunction with the circuit structures shown in FIGS. 1-5 .

Before the electronic product leaves the factory, in order to prolong the storage time of the electronic product, technicians can operate the electronic product to enter a system-wide shutdown mode. Regarding the current state of the electronic product: using the shutdown state or the power-on state, this embodiment proposes two operation modes for controlling the electronic product to enter the system-wide shutdown mode.

If the electronic product is currently in the shutdown state (that is, the main circuit of the system is closed, and the specific function circuit is running), at this time, the electronic product can be controlled to enter the system-wide shutdown mode by pressing the power-on button SW1 and the full-off button SW2 at the same time . When the power-on button SW1 is pressed, the battery voltage VBAT is filtered by the filter capacitor C8, and one of the diodes in the dual-diode device D2 is controlled to conduct forward, and the other diode is reversely cut off, and is transmitted to the first power supply through the conduction diode The enable end CE of the conversion chip U5 controls the first power conversion chip U5 to enable operation and simultaneously charges the energy storage capacitor C4. After the first power conversion chip U5 is enabled to run, it converts the battery voltage VBAT into a system voltage VSYS_3V0 to supply power to the main control chip U2, so that the main control chip U2 starts to run. After the main control chip U2 is turned on, it first detects whether the full shutdown button SW2 is pressed. If the full shutdown button SW2 is not pressed, it is determined that it is required to enter the startup mode. The specific control process will be described in detail in the subsequent sections. If the full shutdown button SW2 is pressed, it is determined that it is required to enter the full system shutdown mode. At this time, the main control chip U2 outputs a high-level active full shutdown signal RTC_LDO_SHUT to control the saturation conduction of the N-channel MOS transistor Q1, and pull down the CE potential of the enable terminal of the second power conversion chip U1 to control the second power conversion chip. U1 stops functioning. At this time, since the second power conversion chip U1 no longer outputs the working voltage RTC_3V0 required by the real-time clock chip U4, the real-time clock chip U4 is powered off and stops running. Then, the main control chip U2 enters a power-off state, and saves data in registers and memories. Since the power-on button SW1 will be disconnected when the technician lets go after pressing and holding it for a period of time, in order to reserve enough time for the main control chip U2 to perform tasks such as starting up, outputting a full shutdown signal RTC_LDO_SHUT, and saving data In this embodiment, the requirement of the working time of the main control chip U2 can be met by properly adjusting the capacitance value of the energy storage capacitor C4 and the resistance value of the discharge resistor R8. That is, when the power-on button SW1 is turned off, the energy storage capacitor C4 is discharged through the discharge resistor R8. During the discharge of the energy storage capacitor C4, the enable terminal CE of the first power conversion chip U5 can still maintain a high-level active state, thereby maintaining the first power conversion chip U5 to continue to operate and supply power to the main control chip U2. When the discharge of the energy storage capacitor C4 ends, the potential of the enable terminal CE of the first power conversion chip U5 becomes low, the first power conversion chip U5 stops running, cuts off the power supply to the main control chip U2, and then controls the main control chip to shut down, by This implements the system-wide shutdown function.

If the electronic product is currently in the power-on state, the electronic product can be controlled to enter the system-wide shutdown mode by pressing the full shutdown button SW2 at this time. When the full shutdown button SW2 is pressed, the system voltage VSYS_3V0 converted and output by the first power conversion chip U5 is transmitted to the P0.28 pin of the main control chip U2 through the closed full shutdown button SW2. When the main control chip U2 detects that the potential of its P0.28 pin becomes high, it determines that it requires to enter the system-wide shutdown mode. At this time, the main control chip U2 first outputs the full shutdown signal RTC_LDO_SHUT to control the second power conversion chip U1 and the real-time clock chip U4 to stop running; secondly, control the shutdown of the peripheral function circuits connected to it; then, the main control chip U2 outputs the The power-on signal PWR_ON_CTL is set to a low level, at this time, the energy storage capacitor C4 is discharged through the discharge resistor R8, and the first power conversion chip U5 is controlled to turn off after maintaining the RC time. During the discharge of the energy storage capacitor C4, the main control chip U2 saves the data of the register and the memory, and when the first power conversion chip U5 is turned off, the whole system enters a shutdown mode.

After the electronic product enters the system-wide shutdown mode, since there is no power consumption, the electronic product can be stored in the warehouse for a long time.

When the electronic product is sold to the consumer for the first time, the power-on button SW1 can be pressed to control the electronic product to start and run. When the power-on button SW1 is pressed, the battery voltage VBAT is first used to control the first power conversion chip U5 to enable operation and supply power to the main circuit of the system. After the main control chip U2 is powered on and running, it outputs a high-level power-on signal PWR_ON_CTL, which is transmitted to the enable terminal CE of the first power conversion chip U5 through the dual diode device D2, so that the first power conversion chip U5 can be turned on even when the power-on button SW1 is turned on. It can also continue to run after disconnection, and always supply power to the main circuit of the system to realize the self-locking function. Then, the main control chip U2 outputs a high-level enable signal RTC_LDO_EN, acts on the enable terminal CE of the second power conversion chip U1 through the anti-reverse bias diode D106 and the current limiting resistor R1, and controls the second power conversion chip U1 to enable Run, output the working voltage RTC_3V0 required by the real-time clock chip U4, and control the power-on operation of the real-time clock chip U4. After the second power conversion chip U1 is enabled to run, the working voltage RTC_3V0 output by the second power conversion chip U1 is applied to the enable terminal CE of the second power conversion chip U1 through the current limiting resistor R3 at the same time, thus, Even when the main control chip U2 is powered off and no longer outputs the high-level enable signal RTC_LDO_EN, the operating voltage RTC_3V0 output by the second power conversion chip U1 itself can be used to keep the second power conversion chip U1 always enabled to run, thereby Ensure that the real-time clock chip U4 can keep running when it is turned on and when it is turned off, so as to ensure the accuracy of timing.

When the consumer starts the electronic product for the first time, the system clock needs to be adjusted. After one adjustment, the real-time clock chip U4 will automatically accumulate time to ensure accurate display of the system clock in the future. After the main control chip U2 controls the start-up of the specific functional circuit, it outputs a control signal to control the start-up of the peripheral function circuit connected to it, and completes the start-up of the product.

After the consumer starts the electronic product once, if the consumer does not want to use it and needs to shut it down, he can call out the shutdown interface by operating the touch screen of the electronic product, and control the electronic product to enter the shutdown state by operating the shutdown interface. When the electronic product enters the shutdown state due to user operation, or automatically shuts down due to insufficient battery power, the main control chip U2 first controls the peripheral function circuit connected to it to shut down, and then sets the power-on signal PWR_ON_CTL to low level to stop supplying power to the first power supply. The conversion chip U5 provides an effective enable signal. Then, the main control chip U2 enters the shutdown state, and saves the data of the register and the memory. After the energy storage capacitor C4 is discharged, the first power conversion chip U5 stops running, cuts off the power supply of the system main circuit, and the system main circuit stops running. The electronic product enters the shutdown state. At this time, since the second power conversion chip U1 and the real-time clock chip U4 are still running, the accuracy of the clock display can be guaranteed when the device is turned on again, and the time does not need to be reset every time the device is turned on.

When the consumer needs to turn it on again after shutting it down, he only needs to press the start button SW1 to control the first power conversion chip U5 to enable operation and supply power to the main circuit of the system. After the main control chip U2 is started, it pulls the power-on signal PWR_ON_CTL high to complete the self-locking of the first power conversion chip U5, and then controls the peripheral function circuits connected to it to start and run to complete the power-on of the electronic product.

Considering that different shutdown modes are applicable to different groups of people, the system-wide shutdown control function of electronic products is not suitable for ordinary consumers. Therefore, in this embodiment, it is preferable to set the full shutdown button SW2 inside the electronic product, for example, built into the product The inside of the housing to avoid consumers touching the operation. The power-on button SW1 is preferably arranged on the casing of the electronic product, or is exposed through a hole on the casing, so as to facilitate operation by consumers.

Of course, the above description is not a limitation of the present utility model, and the present utility model is not limited to the above-mentioned examples. Those of ordinary skill in the art may make changes, modifications, additions or replacements within the essential scope of the present utility model. It should also belong to the protection scope of the present utility model.

Claims (10)

1. A shutdown control circuit, which is used in battery-powered electronic products, in which a power management circuit, a system main circuit, and a specific functional circuit that requires continuous operation when the electronic product is shut down; is characterized in that : The power management circuit is provided with a first power conversion chip for supplying power to the main circuit of the system and a second power conversion chip for supplying power to the specific function circuit; a power-on button and a full shutdown button are arranged on the electronic product , one end of the power-on button is connected to the positive pole of the battery, and the other end is connected to the enable end of the first power conversion chip. When the power-on button is pressed, the first power conversion chip is controlled to enable, and the battery voltage is converted into a system voltage. The system main circuit supplies power; one end of the full shutdown button is connected to the system voltage, and the other end is connected to the system main circuit. When the system main circuit detects that the full shutdown button is pressed, it outputs a full shutdown signal to control the second power conversion The chip stops running, cutting off the power supply of the specific function circuit. 2. The shutdown control circuit according to claim 1, characterized in that: a main control chip and a peripheral function circuit connected thereto are arranged in the main circuit of the system, and the full shutdown button is connected between the battery and the main control between chips. 3. The shutdown control circuit according to claim 1, wherein an energy storage capacitor and a discharge resistor are respectively connected between the enable terminal of the first power conversion chip and the system ground. 4. The shutdown control circuit according to claim 2, characterized in that: the enabling terminal of the first power conversion chip is connected to the cathode of a dual diode device, the cathode of the dual diode device is butted, and the two anodes are respectively connected to the The power-on button and the main control chip are connected in one-to-one correspondence. 5. The shutdown control circuit according to any one of claims 1 to 4, characterized in that: the enabling terminal of the second power conversion chip is connected to a switch circuit, and the switch circuit receives the output from the main circuit of the system When the full shutdown signal is activated, the potential of the enable terminal of the second power conversion chip is pulled down, and the second power conversion chip is controlled to stop running; when the main circuit of the system is turned from the whole system shutdown state to the power on state, the output is high A level-effective enable signal is sent to the enable terminal of the second power conversion chip to control the second power conversion chip to enable operation, and convert the battery voltage into the working voltage required by the specific function circuit, for the specific function circuit. The functional circuit supplies power, and feeds back the output working voltage to the enabling terminal of the second power conversion chip to maintain the continuous operation of the second power conversion chip. 6. The shutdown control circuit according to claim 5, characterized in that: an N-channel MOS transistor is arranged in the switch circuit, the gate of the N-channel MOS transistor receives the full shutdown signal, and the drain The pole is connected to the enabling terminal of the second power conversion chip, and the source is grounded. 7. The shutdown control circuit according to claim 5, wherein the enable signal output by the system main circuit is transmitted to the enable terminal of the second power conversion chip through an anti-reverse bias diode. 8. The shutdown control circuit according to any one of claims 1 to 4, wherein the specific function circuit is a real-time clock circuit, which generates a clock signal and transmits it to the system main circuit. 9. The shutdown control circuit according to any one of claims 1 to 4, characterized in that: the power-on button and the full shutdown button are mechanical buttons without a hold function, and the full shutdown button is installed on the electronic product Inside the shell, the power-on button is exposed to the shell of the electronic product. 10. An electronic product, characterized in that it is provided with the shutdown control circuit according to any one of claims 1 to 9.