JPH04128052U - computer power circuit - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the current consumption associated with computer data retention operations. [Structure] A computer 10 that executes a data retention operation when the main switch 14 is off includes a first regulator 15 for large current and a second regulator 16 for small current, and the computer 10 performs various calculations. When the computer 10 performs an operation, a current from the first regulator 15 is supplied to the computer 10, and when the computer 10 performs a data retention operation, a small current from the second regulator 16 is supplied to the computer 10.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to computer power supply circuits, especially when the main switch is turned off. Used to supply electricity to computers to retain data even after Regarding effective techniques.

0002

[Conventional technology]

Some vehicles such as cars control engine drive based on signals from various sensors. Some models are equipped with a control system. In such systems, the control A microcomputer is used as the controller. This microcomputer A computer consists of logic, processors, memory, etc. Controls engine drive by mechanically linking various calculation operations. It is constructed to

0003 Such in-vehicle microcomputers are usually installed in the battery installed in the car. It is configured to receive power from the battery and perform various calculations. Conventionally, this car battery has a voltage of 12V, 24V, or higher. Due to the high voltage above, the circuit connecting the battery and microcomputer Place a voltage regulator to step down the operating voltage of the microcomputer to 5V. It is necessary to For example, during normal operation, a current of 50 mA is applied to a microcomputer. A current of 5 mA is supplied to the microcomputer during data retention operation. It is now being supplied.

0004 That is, the voltage applied to the microcomputer by the voltage regulator The voltage is held at a constant voltage and during normal operation it is based on the large current from the regulator. The computer performs various calculations. Then the main switch is turned off. When a small current is required for data retention operation from the regulator, the microcontroller Based on this small current, the microcomputer reads data. Execute holding operation. This switching operation prevents wastage of the vehicle battery. That will happen.

[0005]

[Problem that the idea aims to solve]

However, in conventional computer power supply circuits, during normal operation and The current from the same regulator is When the data retention is activated, the regulator Even if the supply current to the regulator is reduced, the control current that constantly flows to the regulator is reduced. As a result, the regulator control current and data retention The on-board battery is wasted due to the current. Therefore, data retention is activated. It is necessary to develop a computer power supply circuit that can reduce power consumption during operation. desired.

[0006] The purpose of this invention is to reduce current consumption during data retention operation. Its purpose is to provide computer power supply circuits.

[0007]

[Means to solve the problem]

The power supply circuit of the computer according to the present invention has various functions when the main switch is on. Performs calculation operations and performs data retention operations when the main switch is off. In the computer power circuit that supplies battery power to the computer hand, Various calculation operations are performed by receiving power from the battery via the main switch. a first regulator that supplies the computer with power necessary for operation; and the battery. The computer receives power directly from the computer and uses only the power necessary for data retention. and a second regulator for supplying power to the computer.

[0008]

[Effect]

According to the above-mentioned means, during normal operation of the computer, the first regulator These currents are supplied to the computer. Then the main switch is turned off. When the computer shifts to data retention operation, the first regulator is turned off. As a result, only the small current required for data retention operation flows from the second regulator to the computer. supplied to the data. The current required for data retention operation is the current required for various calculation operations. Since the current is smaller than , set the control current of the second regulator small. be able to. As a result, the battery current consumption during data retention operation can be reduced. This can be suppressed overall.

[0009]

【Example】

Figure 1 is a circuit diagram showing the power supply circuit of a computer that is an embodiment of the present invention. be.

0010 In this embodiment, the power supply circuit of the computer according to the present invention is used in a vehicle such as an automobile. Supplies power to the microcomputer for the system controller installed in the It is configured to do. The microcomputer that is the core of this controller A computer (hereinafter referred to as CPU) 10 is mounted on a circuit board (not shown). ing. This CPU 10 has various terminals such as a power supply terminal 11 and a gate terminal 12 (some Only the terminals are shown. ), and the power terminal 11 is equipped with a Power from the battery (hereinafter simply referred to as the battery) 13 installed in the vehicle power is supplied to the gate terminal 12, and the gate terminal 12 receives information related to the on/off state of the main switch 14. The signal is now input. Then, battery 13 and power terminal 1 1, the first regulator 15, the second regulator 16, the first A diode 17 and a second diode 18 are provided, and are connected to the main switch 14. A first resistor 19 and a second resistor 20 are provided between the gate terminal 12 and the gate terminal 12 .

[0011] The input side of the first regulator 15 is connected to the battery 13 via the main switch 14. The output side is connected to the power supply terminal 11 via the first diode 17. It is continued. This first regulator 15 is connected to the battery via the main switch 14. Receives power from the telly 13 and outputs the output voltage, for example (hereinafter, regarding voltage and current) same. ) Supplying a current of 50mA to the CPU 10 while maintaining the voltage at 5V. It is configured so that it can be done. At this time, the first regulator 15 has its own A current of about 5 mA flows as a control current for the body.

0012 On the other hand, the input side of the second regulator 16 is directly connected to the battery 13, and the output side is directly connected to the battery 13. The power side is connected to the power supply terminal 11 via the second diode 18 . This second The regulator 16 receives power from the battery 13 and is necessary for data retention operation. The configuration is such that a small current of 1 mA can be supplied to the CPU 10 as a current. has been done. At this time, the second regulator 16 has its own control current. A minute current of about 0.1 mA is allowed to flow. That is, CPU10 When performing various calculation operations, a large current of about 55 mA is drawn from the battery 13. When the CPU 10 executes the data retention operation, the current is as low as 1.1mA. Current will be supplied.

[0013] Further, a first resistor 19 and a second resistor 20 are connected to the gate terminal 12 of the CPU 10. A divided voltage is applied to the main switch 14. When is on, the CPU 10 executes various calculation operations, and the main switch 14 is on. When the CPU 10 is turned off, an off signal applied to the gate terminal 12 causes the CPU 10 to The self-control function causes the device to enter stop mode and perform data retention operations. The sea urchin is turning.

[0014] Next, the effect will be explained. When the main switch 14 is on, the voltage applied to the gate terminal 12 The CPU 10 executes various calculation operations. At this time, the CPU 10 A large current of about 50 mA is supplied from the regulator 15 as the current required for various calculation operations. Supplied.

[0015] Next, when the main switch 14 is turned off, an off signal is input to the gate terminal 12. The CPU 10 uses its self-control function to shift to stop mode and restart the device. Executes data retention operation. At this time, the main switch 14 is turned off, so The first regulator 15 becomes inactive. Therefore, the CPU 10 has a second Only a small current from regulator 16 will be supplied. Moreover, the second level The control current of the regulator 16 is much smaller than the control current of the first regulator 15. The battery 13 is consumed while the CPU 10 executes the data retention operation. The overall current will be suppressed to a much lower level. In other words, battery 13 waste will be effectively suppressed.

[0016] It should be noted that the present invention is not limited to the above-mentioned embodiments, and there may be no deviation from the gist of the invention. It goes without saying that various changes can be made within a reasonable range. For example, in the embodiment, a computer installed in a vehicle such as an automobile Although this invention is not limited to this example, it can also be applied to portable personal computers. A computer that is connected to a microcomputer, phone computer, etc. It can be applied to all power supply circuits.

[0017]

[Effect of the idea]

As explained above, according to the present invention, the first regulator for large current and the first regulator for small current A second regulator is provided for use when the computer performs various calculation operations. To supply a large current from the first regulator to the computer, the computer When performing a data retention operation, a small current is supplied from the second regulator. This configuration minimizes current consumption associated with data retention operations. This can reduce battery waste.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a power supply circuit of a computer that is an embodiment of the present invention.

[Explanation of symbols]

10...CPU (computer), 11...power terminal, 12
...gate terminal, 13...vehicle battery, 14...main switch, 15...first regulator, 16...second regulator, 17, 18...diode, 19, 20...resistance.

Claims (1)

[Scope of utility model registration request] 1. In a computer power supply circuit that supplies power to a computer that executes various arithmetic operations when a main switch is on and executes data retention operations when the main switch is off, power from the battery is supplied to the main computer. a first regulator that receives power through a switch and supplies the computer with power necessary for various arithmetic operations; and a second regulator that directly receives power from the battery and supplies the computer with only the power necessary for data retention operations. A computer power supply circuit comprising: