JPH11352195A - Power source device for voltage margin test - Google Patents

Abstract

PROBLEM TO BE SOLVED: To economically execute voltage margin test even on an inexpensive product by inserting a power source device for voltage margin test between a power source device and a logic substrate or a power source wire of a device. SOLUTION: A step-down converter is formed by a transistor 5, a diode 6, a coil 7 and the capacitors 10, 11, the transistor 5 is driven in a PWM(pulse width control) mode by a control circuit 12, and the test voltage is stepped down and stabilized to the DC voltage of a power source device of an information processing unit to be tested. Further a voltage booster converter 10 formed by a coil 7, a transistor 8, a diode 9 and a capacitor 10 continuously switches the transistor 5 ON, and the transistor 8 is driven in the PWM mode for converting the test voltage into the voltage above the output voltage of the information processing unit. The power source device for voltage margin test having this structure, is inserted and connected between a power source device of the information processing unit and a device or a logic substrate, and the voltage margin and the noise margin are confirmed by changing the output voltage, the switching frequency, the output ripple and the noise.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a power supply for testing which is effective at the time of evaluation of an information processing apparatus and testing or troubleshooting.

[0002]

2. Description of the Related Art When testing the function of a device such as a logical board of an information processing apparatus or a connected hard disk, or troubleshooting for investigating the cause of an intermittent failure, the logical board or the device is required. On the other hand, a method of changing the supplied DC voltage and confirming the voltage margin is often used.

An example of the prior art is described in Japanese Patent Application Laid-Open No. 5-158572, "Clock / Voltage Margin Test System".

In the prior art, this voltage margin test is combined with a clock frequency fluctuation test of a logic device, and is to be performed automatically.

According to this method, a voltage margin test can be performed very efficiently. Further, this is a high-performance test method capable of storing the abnormal stop contents of the information processing apparatus and tracing a limit point.

[0006]

Although the voltage margin test method according to the prior art is highly functional and efficient, the power supply device mounted on the information processing device must naturally have an interface for changing the voltage with respect to the command. is there.

In recent years, high-integration technology has enabled low-cost, high-performance logic boards and devices to be provided. Further, reliability has been improved, and the voltage margin test is necessarily performed on all information devices to be manufactured. It is no longer necessary.

Further, by adding a command voltage variation function to a power supply device as compared with a logic board or a device at a lower cost, the balance between cost increase and additional function becomes a problem especially in a low-cost product.

[0009] It is difficult to mount a function to be used only at the time of development evaluation or at the time of occurrence of a trouble in all products that produce it, especially in low-cost products.

The present invention seeks to economically perform a voltage margin test even on low-cost products.

[0011]

A solution according to the present invention is an inexpensive information processing apparatus. If the logic board and the power supply apparatus do not have a voltage margin test interface, the power supply apparatus and the logic board or device can be used. By inserting the power supply for voltage margin check into the power supply line,
A voltage margin test is performed.

A power supply according to the present invention is inserted and connected to a power supply line for supplying a DC voltage from a power supply mounted on an actual product to a logic board or a device, and the input voltage from the equipment mounted power supply is stepped up or down. Convert and supply to logic boards and devices.

[0013]

1 and 2, an embodiment of the present invention will be described.

FIG. 1 is a circuit diagram of an embodiment of a power supply for a voltage margin test according to the present invention.

DC IN is an input section of the test power supply according to the present invention, and is connected to the DC output of the power supply of the information processing apparatus for performing a margin test.

The transistor 5, diode 6, coil 7, capacitor 10, and capacitor 11 form a buck converter. In this step-down converter, the control circuit 12 drives the transistor 5 in a PWM (pulse width control) mode,
The output voltage of the test power supply according to the present invention is stepped down and stabilized by the drive duty of the control circuit with respect to the DC output of the power supply of the information processing apparatus. When operating as a step-down converter, the transistor 8 maintains the OFF state.

The coil 7, the transistor 8, the diode 9, the capacitor 10, and the capacitor 11 form a boost converter. When operating as a boost converter, the transistor 5 is continuously maintained in the ON state, and the transistor 8 is driven by PWM of the control circuit 12 so that the output voltage of the test power supply according to the present invention is changed by the output voltage of the information processing apparatus. It can be converted to high voltage.

The control circuit 12 controls the transistors 5 and 8 by PWM driving as described above to control the output voltage. The output voltage is controlled by changing the feedback loop, particularly the error detection resistor 14 for detecting the output voltage. Can be changed. This operation is also a basic operation in a power supply device having feedback control.

It is needless to say that this voltage change adjustment can be automated using external information as described above.

The operation margin for the quality of the supply voltage of the information processing apparatus is determined not only by the DC voltage level of the supplied DC voltage (the DC voltage level is an average value of the supplied voltage (voltage excluding the AC component) but also by the supply voltage). It is also greatly affected by the AC component contained in the voltage (AC voltage frequency and AC voltage value). Of course, if the DC power supply mounted on the device outputs only the DC component and does not generate an AC voltage called ripple or noise, there is no need to perform an operation margin test on the AC component.

Most of today's DC power supplies for devices employ a pulse mode control converter called a switching power supply, so that a certain amount of AC voltage is superimposed on a predetermined DC voltage and sent to the control unit of the information processing device. Even from the fact that it is supplied, this AC voltage (ripple, noise)
It is important to check the operation margin of the device with respect to.

Although the function of the DC voltage fluctuation can be incorporated into the power supply mounted on the information processing apparatus in the above-mentioned conventional technology, there is no prior art about the fluctuation of the AC voltage level. The test power supply apparatus of the present invention can provide a means for confirming the operation margin of the information processing apparatus even with respect to the AC voltage fluctuation.

The resistor 13 is an adjusting resistor for changing the frequency for driving the transistors 5 and 8.
An object of the present invention is to change the oscillation frequency of a PWM control circuit of a test power supply according to the present invention by changing a time constant, and to change the switching frequency of the test power supply according to the present invention, that is, the frequency of the AC voltage. Can also be evaluated.

It is possible to confirm whether or not the information processing device malfunctions at a specific AC voltage frequency. Of course, the resistance value can be controlled from the outside in the same manner as the voltage fluctuation.

Further, the coil 7, the capacitor 10, and the capacitor 11 can be replaced with other components, and the amount of noise can be changed. The coil 7, the capacitor 10, and the capacitor 11 form a low-pass filter, ideally for the purpose of passing only the DC component and blocking the DC component. An ideal filter has an infinite inductance of the coil 7, an infinite capacitance of the capacitors 10 and 11, and
It is desirable that coils and capacitors are composed of ideal parts without stray capacitance, stray inductance, and resistance components, but actual products have finite values,
Has floating components and resistance (loss).

By replacing this filter component, the DC voltage component can be increased or decreased, and the operation margin (malfunction level) of the device with respect to the AC voltage component can be confirmed in combination with the frequency fluctuation.

Since the test power supply according to the present invention is externally inserted between the internal power supply of the information processing apparatus and the logic board or the I / O device, such a power component can be replaced.

FIG. 2 shows the actual operation.

As shown, the power supply 1 of the information processing apparatus
A power supply for voltage margin test according to the present invention is inserted and connected to a power supply line between the device or the logic board 2 and the output voltage, switching frequency, output ripple, and noise of the power supply are changed by the above-described method. The voltage margin and the noise margin can be checked.
This confirmation work can be applied to evaluation during product development and line inspection during mass production, and can also be used for troubleshooting in the event of a failure.

[0030]

By using the power supply for voltage margin test according to the present invention, a voltage margin test can be performed even in a low-cost information processing device even if the built-in power supply does not have a voltage change interface by a command or the like. Become.

Further, by adding a function of changing a frequency and changing a filter component to the power supply for voltage margin test, not only a voltage margin test but also a simple noise margin can be confirmed. An evaluation test or troubleshooting of the apparatus can be economically performed.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a power supply for a voltage margin test according to the present invention.

FIG. 2 is a connection diagram of a voltage margin test in the information processing apparatus according to the present invention.

[Explanation of symbols]

1. Power supply device with built-in information processing device, 2. Power supply device for voltage margin test, 3. Device under test.

Claims (3)

[Claims] 1. A step-up / step-down switching power supply is inserted into a power supply line between a logical board, an input / output control device, a storage device, or a file device of an information processing device and a power supply device built in the information processing device. A voltage margin test power supply, which performs a voltage margin test of the logic board or the device. 2. The power supply device for voltage margin test, wherein a voltage conversion switching frequency can be changed. 3. The power supply device for voltage margin testing, wherein output filter constants (coils and capacitors) are made variable to enable changes in output noise level.