JPH08320740A - Power circuit of portable information processor - Google Patents

Abstract

PURPOSE: To provide a power unit which delays the timing of electricity feeding to respective device and is designed with relatively small power source capacity by varying the constant values of the resistance and capacitor of a power source controller consisting of the resistance and capacitor. CONSTITUTION: Of the power circuit of the portable information processor, a device 1 connects with a main substrate, a device 2 connects with a hard disk, and a device 3 connects with a device which consumes large electric power like a floppy disk. As circuits which control the power sources of the respective devices 1-(n), the device 1 consists of a circuit composed of a resistance R1 and a capacitor C1, the device 2 consists of a circuit of R2 and C2, and a device (n) consists of a circuit of Rn and Cn. Those device require peak currents almost at the same time, so the constants of R1-Rn and C1-Cn are made different to supply electric power to the devices 1-(n) at different time, thereby saving the electric power.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can be applied to a personal computer such as a notebook or a palmtop personal computer, which is required to be lightweight and small in size, without making the power supply have an unnecessarily large margin and at low cost. Utilizing the delay due to the RC time constant, which can be easily changed for adjustment, at system startup,
When power is applied to a device when it is resumed, by slightly shifting the power-on timing of each device, it is possible to prevent the peaks of the current consumption of each device from overlapping, and as a result, use the power supply with the minimum required capacity. The present invention relates to a power supply circuit of a portable information processing device that prevents a power supply voltage from dropping at the time of device startup and realizes a safe resume.

[0002]

2. Description of the Related Art In a power supply circuit of a conventional portable information processing device, a battery-operated personal computer such as a notebook personal computer or a palmtop personal computer is required to be small and lightweight, and a power source section is also required to be space-saving. Therefore, when power is supplied to each device at the time of system startup, the peak current of each device flows simultaneously. Further, these computers have a function such as suspend as a means for power saving, and the power of each device can be turned on / off as necessary. Therefore, the power consumption is reduced by turning off the power supply of the device as much as possible during the suspend. On the contrary, at the time of resume, the power supplies of these turned off devices are turned on all at once, and the power supplies are required to have the ability to follow a sudden load change at this time. Therefore, conventionally, (1) the power supply capacity is provided with a margin. This method is to design a power supply that can supply the total peak current at the time of starting each device, and to make the power supply have a capacity larger than the maximum current during normal use.

(2) The power supply of each device is controlled by a separate system, and the power-on timing is controlled by software or hardware. In this method, the power-on timing of each device can be controlled separately, so the power-on timing can be reduced by shifting the power-on timing.

[0004]

However, in the power supply circuit of such a portable information processing apparatus, the above method (1) can start and resume the system most safely. However, the capacity of the power supply becomes large, which is disadvantageous for a personal computer that is required to be small and lightweight. Moreover, the cost of the power source becomes high, and the price cannot be lowered.

According to the method (2), the power source can be downsized, but the control by software imposes a heavy load on the software, and when adjustment is required, the software must be changed and masked. ROM etc.
The mask will be changed and the cost will increase. Similarly, even in the case of control by hardware, it is necessary to change the mask of the LSI that performs control, which also raises the problem of cost increase.

[0006]

The present invention is intended to solve these problems, and is a battery-powered portable information device having a built-in device such as a hard disk or a floppy disk which requires large power consumption at the time of startup. In a power supply circuit of a processing device, a power supply control for controlling a power supply sequence of each device, and the power supply control is composed of a resistor and a capacitor. The power supply to each device is turned on based on a constant value of the resistor and the capacitor. Provided is a power supply circuit for a portable information processing device, which is characterized by delaying timong.

[0007]

According to the present invention, a circuit for controlling a power supply sequence to a device in which a hard disk drive or a floppy disk, which requires a large amount of power consumption at the time of start-up in a battery-powered portable information processing device, has a resistor and a capacitor. It is possible to shift the timing of power-on to each device by changing these constants, so that it is possible to design with a relatively small power supply capacity. Therefore, a system that is advantageous in terms of cost and space can be provided.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a power supply circuit of a portable information processing device of the present invention, and FIG. 2 is a diagram illustrating a peak current of a device used in the power supply circuit of the portable information processing device of the present invention. FIG. 3 is a diagram for explaining the operation of the power supply circuit of the portable information processing device of the present invention.

In the power supply circuit of the portable information processing apparatus of the present invention shown in FIG. 1, DEVICE1 (device 1) has a large capacity such as a main substrate, DEVICE2 (device 2) has a hard disk, and DEVICE3 (device 3) has a large capacity like a floppy disk. A device that uses power is connected. As a circuit for controlling the power supply of each of these devices, a resistor (R), a capacitor (C) and a switch (FET) are provided for each device.
SW) is provided. R for device 1
1, C1 and R2 and C2 for the device 2, and R3 and C3 for the device 3.
The operation will be described based on FIGS. 1 to 3.

In FIG. 2, the horizontal axis represents time and the vertical axis represents current value. (A) shows the peak current when the device 1 starts up, (b) shows the peak current when the device 2 starts up, and (c) shows the peak current when the device 3 starts up. As can be seen in FIG. 2, these devices require peak currents at approximately the same time, thus requiring large capacity batteries. Therefore, in order to solve this problem, the present invention delays the power supply time to each device by setting constants in R1, C1, R2, C2, R3 and C3.

For example, when the time constants of R1 = 1KΩ, C1 = 10 μF R2 = 0Ω, C2 = not used R3 = 560Ω and C3 = 10 μF are set, the delay times are t1 = 0.01 seconds and t2, respectively. = 0 seconds, t3 = 0.005
It will be 6 seconds. From the above, as shown in FIG. 3A, each peak current is generated based on the delay time as described above. A combination of these peak currents is shown in FIG. As can be seen from this figure, since the peak current is delayed and a large current is not generated at one time, a small battery can be used.

[0012]

As described above, the present invention controls the power supply sequence to a device in which a hard disk drive or a floppy disk, which requires a large power consumption at the time of startup, is incorporated in a battery-powered portable information processing apparatus. It is possible to design with a small power source capacity by delaying the power-on timing of each device by changing the constants of the circuit resistance and capacitor, and it is possible to provide a system that is advantageous in terms of cost and space.

[Brief description of drawings]

FIG. 1 is a block diagram of a power supply circuit of a portable information processing device according to the present invention.

FIG. 2 is a diagram illustrating a peak current of a device used in a power supply circuit of a portable information processing device according to the present invention.

FIG. 3 is a diagram for explaining the operation of the power supply circuit of the portable information processing device according to the present invention.

[Explanation of symbols]

 R1, R2, R3 resistors C1, C2, C3 capacitors

Claims (1)

[Claims] 1. A power supply control circuit for controlling the power supply sequence of each device in a power supply circuit of a portable information processing device which has a built-in device such as a hard disk or a floppy disk which requires a large amount of power consumption at startup and is driven by a battery, A power supply circuit for a portable information processing device, wherein the power supply control is composed of a resistor and a capacitor, and delays the power-on timing of each device based on the constant values of the resistor and the capacitor.