A method for preventing black screen, distorted screen and system data loss caused by power drop

Abstract

The present invention discloses a method for preventing a black screen, a distorted screen, and system data loss caused by power drop, which uses a small signal NMOS tube to drive and control PMOS as a power anti-reverse circuit to prevent the battery power-off current from flowing back to the battery and increase the load capacity; an LC oscillation circuit is used to store energy during circuit oscillation; a power monitoring chip circuit controls the opening and closing of the PMOS power anti-reverse circuit, and sends instructions to the power abnormal interruption information circuit. The problem of black screen, distorted screen, and system data loss caused by power drop due to various reasons is effectively solved. The present invention also provides a system for preventing a black screen and distorted screen caused by a power drop pulse experiment.

Description

Technical Field

[0001] The present invention relates to a vehicle battery power supply detection technology, and in particular to a method and a system for preventing a black screen, a distorted screen, and system data loss caused by a power drop, and belongs to the field of power supply technology. Background Art

[0002] With the rapid development of automotive electronic technology, the technology of carrying multiple large screens on a car computer has been widely adopted, resulting in a sharp increase in the overall power consumption of the car computer, so it is necessary to test the power supply of the car computer. According to the relevant technical standards of the car manufacturer, various power pulse and other related experiments need to be carried out on the car computer. In the power drop pulse experiment, especially the simulated engine crank experiment, there is a possibility that the power supply drops to the minimum voltage requirement range allowed by the car computer instantly, causing the car computer to lose power instantly, and problems such as black screen and flower screen appear after the instant start, and even cause system data loss, and the car computer cannot start normally.

[0003] At present, the method commonly used in existing technology is to directly connect a high-current diode at the power input end to prevent reverse flow. However, as the current of the domain controller increases, the voltage drop inside the diode will also increase, which will affect the acquisition accuracy of the power supply of the subsequent circuit and affect the stability of the system. CN202021000877.8 A power supply circuit that meets the power drop performance requirements is disclosed, including a power input module, an isolation energy storage module, a filtering energy storage module, a voltage conversion module and an output module that are electrically connected in sequence, wherein the filtering energy storage module includes more than one first filtering energy storage unit connected in series, and the filtering energy storage unit includes a common-mode inductor and one or more capacitors that meet the load power supply requirements for a certain period of time, and the input end of the common-mode inductor is connected to the output end of the isolation energy storage module, and the two ends of the capacitor are connected in parallel to the two output ends of the common-mode inductor. Among them, the isolation module used is a diode, and the current of the domain controller itself is very large. Due to the characteristics of the diode itself, the voltage drop inside the diode will also increase, which will affect the acquisition accuracy of the power supply of the subsequent circuit and affect the stability of the system.

[0004] Therefore, how to solve the problem that the power supply of the front stage of the vehicle computer affects the black screen, the distorted screen and the loss of system data during the power drop pulse test of the vehicle battery power detection is a problem to be solved by technical personnel in this field. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a method for preventing a black screen, a distorted screen and system data loss caused by a power drop.

[0006] Furthermore, the present invention also provides a system for implementing the method to prevent a black screen, a distorted screen, and system data loss caused by a power drop.

[0007] To achieve the above purpose, the present invention adopts the following technical solutions:

[0008] A method for preventing black screen, screen distortion and system data loss caused by power drop, using a small signal NMOS tube to drive and control PMOS as a power anti-reverse circuit to prevent the battery power-off current from flowing back to the battery and increase the load capacity; using an LC oscillation circuit to store energy during circuit oscillation; a power monitoring chip circuit controls the opening and closing of the PMOS power anti-reverse circuit, and sends instructions to the power abnormal interruption information circuit. The load includes the SOC and various peripheral chips carried by the vehicle computer.

[0009] Furthermore, when the power detection chip circuit detects that the input voltage is lower than the set value, the locomotive protection sleep state;

[0010] When the power detection chip circuit detects that the input voltage is higher than the set value, the locomotive works normally;

[0011] When doing the power drop pulse experiment, when the power detection chip circuit detects that the input voltage is higher than the set value, the parallel PMOS tube and the small signal NMOS tube are both turned on, the vehicle is powered on and continues to work normally; when the power detection chip circuit detects that the input voltage is lower than the set value, the power detection chip circuit turns off the small signal NMOS tube, and the NMOS tube quickly turns off the PMOS tube at this time; the power detection chip circuit outputs an interrupt signal to the MCU through the conversion circuit at the same time, the MCU sends the information to the SOC, and the SOC starts to back up data; the MCU starts to start the power-off timing process, so that the locomotive enters a dormant state. Among them, the set value of the input voltage is the threshold value of 6V required for normal operation in the vehicle standard.

[0012] The present invention also provides a system for preventing a black screen, a flowery screen and system data loss caused by a power drop, comprising a PMOS power anti-reverse circuit, an LC oscillation circuit, a power monitoring chip circuit and a power abnormal interruption information circuit; the PMOS power anti-reverse circuit uses a small signal NMOS tube to drive and control the PMOS as a power anti-reverse circuit to prevent the battery power-off current from flowing back into the battery and increase the load capacity; the LC oscillation circuit is used to store energy during circuit oscillation; the power monitoring chip circuit controls the opening and closing of the PMOS power anti-reverse circuit and sends instructions to the power abnormal interruption information circuit at the same time.

[0013] Furthermore, a small capacitor and a diode are added to the front stage of the PMOS as a slow-start circuit to prevent the instantaneous impact of the instantaneous large current on the subsequent chips and devices. A large capacitor is added to the back stage of the PMOS to maintain the power supply in the state of instantaneous power drop, ensuring that there is enough time for the vehicle computer to complete the power-off sequence and system file backup normally. The back end of the power monitoring chip circuit is also connected to the circuit MCU, which is connected to the SOC.

[0014] The power monitoring chip circuit adopts the BD48E35G-MTR detection chip and its peripheral circuits.

[0015] The present invention also provides an application of the system for preventing a black screen, a distorted screen, and system data loss caused by a power drop, which is used for detecting the power status of a vehicle battery.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The method of preventing black screen, flower screen and system data loss caused by power drop of the present invention adopts a small signal NMOS tube to drive and control PMOS as a power anti-reverse circuit to prevent the battery power-off current from flowing back to the battery and increase the load capacity; an LC oscillation circuit is used to store the energy when the circuit oscillates; the power monitoring chip circuit controls the opening and closing of the PMOS power anti-reverse circuit, and sends instructions to the power abnormal interruption information circuit. The problem of black screen, flower screen and system data loss caused by power drop due to various reasons is effectively solved. The load includes the SOC and various peripheral chips carried by the vehicle machine. The method of connecting two PMOS tubes in parallel is used as the power anti-reverse design and increases the load capacity. The characteristics of PMOS are small internal resistance, low voltage drop of PMOS under large current, and more accurate power supply voltage acquisition for the later stage. Since the characteristics of PMOS are bidirectional conduction, only using PMOS for anti-reverse in the power instantaneous drop pulse experiment cannot provide effective protection, so a power detection chip is added to monitor the power supply. The present invention adopts ROHM's BD48E35G-MTR detection chip and an NMOS to instantly shut down the PMOS to protect the power supply of the vehicle computer.

[0018] 2. The present invention also provides a system to prevent black screen, screen distortion and system data loss caused by power drop. A small capacitor and a diode are added to the front stage of PMOS as a slow-start circuit to prevent instantaneous large current from instantly impacting the subsequent chips and devices. A large capacitor is added to the rear stage of PMOS to maintain the power supply in the state of instantaneous power drop, ensuring that there is enough time for the vehicle computer to normally complete the power-off sequence and system file backup.

[0019] 3. The power monitoring chip circuit of the present invention uses the BD48E35G-MTR detection chip with a detection voltage of 3.5V. When the VDD pin voltage is below 3.5V, VOUT is pulled down; when the VDD pin voltage is above 3.5V, VOUT is in an open-drain output. Since the maximum withstand voltage of the VDD and VOUT pins is 10V, it is necessary to add a voltage regulator to protect the pins. In addition, the battery voltage must reach 6V or above after startup to start the vehicle normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a circuit principle block diagram of the present invention;

[0021] Figure 2 It is the control flow chart of the circuit principle of the present invention;

[0022] Figure 3 It is a circuit schematic diagram of a specific implementation mode of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the embodiment of the present invention clearer, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. It is usually described in the drawings here and the combination of the embodiments of the present invention can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] In the present invention, the relevant technical terms are defined as follows:

[0025] Serial number Symbol / English Chinese Function or meaning 1 CRANK start up This shows the power supply simulation experiment of engine starting 2 MCU Microcontroller unit Control chip 3 SOC System-on-Chip Runs operating system and data processing chip 4 ROHM Roma Chip manufacturers

[0026] See also Figure 1 and Figure 2 The present invention provides a method for preventing a black screen, a distorted screen, and system data loss caused by a power drop. A PMOS tube and an NMOS tube connected in parallel are used as a power reverse protection circuit. The PMOS is driven and controlled by a small signal NMOS tube to prevent the battery power-off current from flowing back into the battery and increase the load capacity. At the same time, a power detection chip is added to monitor the power supply.

[0027] When the power detection chip detects that the input voltage is lower than the set value, the locomotive protection sleep state;

[0028] When the power detection chip detects that the input voltage is higher than the set value, the locomotive works normally;

[0029] When doing the power drop pulse experiment, when the power detection chip detects that the input voltage is higher than the set value, the parallel PMOS and NMOS tubes are turned on, the locomotive is powered on and continues to work normally; when the power detection chip detects that the input voltage is lower than the set value, the power detection chip turns off the NMOS tube and the NMOS tube turns off the PMOS tube; at the same time, the MCU sends information to the SOC, and the SOC starts to back up data; the MCU starts to start the power-off timing process to put the locomotive into a sleep state.

[0030] like Figure 1As shown, the present invention provides a system to prevent black screen, screen distortion and system data loss caused by power drop, including a PMOS power anti-reverse circuit, an LC oscillation circuit, a power monitoring chip circuit and a power abnormal interruption information circuit; the PMOS power anti-reverse circuit uses a small signal NMOS tube to drive and control the PMOS as a power anti-reverse circuit to prevent the battery power-off current from flowing back to the battery and increase the load capacity; the LC oscillation circuit is used to store energy during circuit oscillation; the power monitoring chip circuit controls the opening and closing of the PMOS power anti-reverse circuit, and sends instructions to the power abnormal interruption information circuit at the same time. The PMOS power anti-reverse circuit includes a parallel PMOS tube and an NMOS tube and its peripheral circuits, the parallel input end of which is connected to the power input module, and the output end is connected to the load; the NMOS tube is also connected in parallel with a power detection chip to monitor the input power to control the opening and closing of the NMOS tube and the PMOS tube. A small signal NMOS tube is used to drive and control the PMOS to prevent the battery power-off current from flowing back to the battery and increase the load capacity; the load includes the SOC and various peripheral chips carried by the vehicle computer.

[0031] Furthermore, a small capacitor and a diode are added to the front stage of the PMOS as a slow-start circuit to prevent the instantaneous impact of the instantaneous large current on the subsequent chips and devices. A large capacitor is added to the back stage of the PMOS to maintain the power supply in the state of instantaneous power drop, ensuring that there is enough time for the vehicle computer to complete the power-off sequence and system file backup normally. The back end of the power monitoring chip circuit is also connected to the circuit MCU, which is connected to the SOC.

[0032] See also Figure 3 , which is a specific implementation method of the present invention for preventing a black screen, a flowery screen and system data loss caused by a power drop pulse experiment; wherein the power monitoring chip circuit adopts a BD48E35G-MTR detection chip and its peripheral circuits.

[0033] A large capacitor is added to the PMOS back-end to maintain the power supply in the state of instantaneous power drop, ensuring that there is enough time for the vehicle computer to complete the power-off sequence and system file backup normally. The back-end of the power monitoring chip circuit is also connected to the circuit MCU, which is connected to the SOC. The large capacitor is generally selected after calculation based on the load current of the back-end, and a 3300uF capacitor is selected in the present invention.

[0034] It is used to detect the power status of the vehicle battery. By adding a voltage divider resistor to the VDD pin, the battery critical detection voltage can be designed to be 6V. When the battery voltage is lower than 6V, the VOUT pin is instantly pulled low; when the battery voltage is above 6V, VOUT is in an open-drain output, and the vehicle computer can work and be awakened at this time. Therefore, the output state of the VOUT pin can be used as the battery detection state, and the detection signal is input to the MCU as a battery monitoring signal.

[0035] During the power drop pulse test or engine CRANK test, the battery voltage is instantly pulled down. At this time, after the VDD voltage is divided by the voltage divider resistor and is lower than 3.5V, the VOUT pin is instantly pulled down, turning off the NMOS, thereby turning off the PMOS to prevent current backflow. At this time, the large capacitor of the subsequent stage provides power to ensure that the load has enough time to shut down and backup system data. After the power drop, the power supply starts instantly (the intermediate drop time is very short) and when the power supply reaches more than 6V, the VOUT pin opens the drain output again, turning on the NMOS, thereby turning on the PMOS to continue to supply power to the subsequent load chip.

[0036] It is necessary to add a 3.3V constant voltage to the VDD pin to prevent the BD48E35G-MTR chip from failing after a power outage, which will cause the entire power supply network to fail. The reason for choosing a 3.3V constant voltage is that 3.3V is lower than the chip's detection voltage of 3.5V and the general power supply of the MCU is 3.3V, which is relatively common. If the power is restored after a momentary power outage, the capacitance value of the MCU battery detection interrupt port can be appropriately increased to prevent the car computer from shutting down by mistake.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Those skilled in the art should understand that those modifications or equivalent substitutions of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution should be included in the scope of the claims of the present invention.

Claims

1. A system to prevent a black screen, a distorted screen, and system data loss caused by a power drop in a locomotive, characterized in that: It includes a PMOS power anti-reverse circuit, an LC oscillation circuit, a power monitoring chip circuit and a power abnormal interruption information circuit; the PMOS power anti-reverse circuit uses a small signal NMOS tube to drive and control the PMOS to prevent the battery power-off current from flowing back to the battery and increase the load capacity; the LC oscillation circuit is used to store energy during circuit oscillation; the power monitoring chip circuit controls the opening and closing of the PMOS power anti-reverse circuit and sends instructions to the power abnormal interruption information circuit at the same time; When the power detection chip circuit detects that the input voltage is lower than the set value, the locomotive protection sleep state; When the power detection chip circuit detects that the input voltage is higher than the set value, the locomotive works normally; When doing the power drop pulse experiment, when the power detection chip circuit detects that the input voltage is higher than the set value, the parallel PMOS tube and the small signal NMOS tube are both turned on, the locomotive is powered on and continues to work normally; when the power detection chip circuit detects that the input voltage is lower than the set value, the power detection chip circuit turns off the small signal NMOS tube, and the NMOS tube quickly turns off the PMOS tube at this time; the power detection chip circuit simultaneously outputs an interrupt signal to the MCU through the conversion circuit, the MCU sends the information to the SOC, and the SOC starts to back up data; the MCU starts to start the power-off timing process, so that the locomotive enters a dormant state; The set value of the input voltage is the threshold value of 6V required for normal operation in the vehicle computer standard.

2. The system for preventing a black screen, a distorted screen, and system data loss caused by a power drop of a locomotive according to claim 1 is characterized in that: A small capacitor and a diode are added before the PMOS as a slow-start circuit.

3. The system for preventing a black screen, a distorted screen, and system data loss caused by a power drop of a locomotive according to claim 1 is characterized in that: A large capacitor is added after the PMOS to maintain the power supply in the event of a momentary power drop.

4. The system for preventing a black screen, a distorted screen, and system data loss caused by a power drop of a locomotive according to claim 1 is characterized in that: The rear end of the power monitoring chip circuit is also connected to a circuit MCU, and the circuit MCU is connected to the SOC.

5. The system for preventing a black screen, a distorted screen, and system data loss caused by a power drop of a locomotive according to claim 1 is characterized in that: The power monitoring chip circuit adopts the BD48E35G-MTR detection chip and its peripheral circuits.

6. The system for preventing a black screen, a distorted screen, and system data loss caused by a power drop of a locomotive according to claim 1 is characterized in that: The load includes the SOC carried by the vehicle computer and various peripheral chips.

7. A method for preventing a black screen, a distorted screen, and system data loss caused by a power drop in a locomotive, characterized in that: A system for preventing black screen, distorted screen and system data loss caused by power drop as described in any one of claims 2 to 6 is used for detecting the power status of a vehicle battery.

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