1. Technical Field
The present disclosure relates to protection circuits and, more particularly, to a protection circuit to protect motherboards from being damaged when working voltages are abnormal.
2. Description of Related Art
Motherboards in computers are easily damaged when working voltages are abnormal, for example, when working voltages are interrupted or spike high. Also, it is difficult to know where the working voltage is abnormal, which increases investigation and repair difficulties.
Therefore, it is desirable to provide a protection circuit to protect motherboards from being damaged when working voltages are abnormal.
The drawing is a schematic diagram showing a protection circuit in an embodiment.
Embodiments of the disclosure will be described with reference to the drawing.
Referring to the drawing, a protection circuit 30 is connected to a voltage supply module 10 and a motherboard 20. The voltage supply module 10, the motherboard 20, and the protection circuit 30 may be applied in an electronic device 1, such as a computer.
The voltage supply module 10 includes several voltage chips 101 such as voltage regulators for supplying different input voltages, such as 1.2V, 1.5V, 3V, and 5V. In this embodiment, the number of the voltage chips 101 is m (m is a positive integer). Each voltage chip 101 includes an enable pin ENABLE for enabling or disabling the voltage chip 101. When the voltage chip 101 stops outputting the corresponding input voltage when disabled.
The motherboard 20 is connected to the voltage supply module 10 to obtain the input voltages and includes several working chips 201 and a Southbridge 202. The number of the working chips 201 in this embodiment is n (n is a positive integer). Each working chip 201 works properly when a working voltage, which is one of the input voltages, supplied thereto falls within a predetermined range and malfunctions, or even is damaged, when the working voltage exceeds the predetermined range, that is, the working voltage is abnormal. The Southbridge 202 includes a power button pin PWRBTN# and is configured to shut down the electronic device 1 when the power button pin PWRBTN# is signaled.
The protection circuit 30 includes an embedded control chip (ECC) 301 and an indicating circuit 302.
The ECC 301 includes a number of detecting pins 3011, a number of first control pins 3012, a second control pin 3013, and a number of third control pins 3014.
The number of the detecting pins 3011 is same as the number of the working chips 201. Each of the detecting pins 3011 is connected to one of the working chips 201 to read the working voltage of one of the working chips 201.
The number of the first control pins 3012 is same as the number of the voltage chips 101. Each of the first control pins 3012 is connected to the enable pin ENABLE of one of the voltage chips 101.
The second control pin 3013 is connected to the power button pin PWRBTN# of the Southbridge 202.
The number of the third control pins 3013 is same as the detecting pins 3011. Each third control pin 3014 is associated with one of the detecting pins 3011.
All of the detecting pins 3011, the first control pins 3012, the second control pin 3013, and the third control pins 3014 of the ECC 301 may be general purpose input/output (GPIO) pins.
The indicating circuit 302 includes a number of paths 302p. The number of the paths 302p is the same as the number of the third control pins 3014. Each path 302p includes a current limiting resistor 3021 and an indicator 3022 such as a light emitting diode connected in series between one of the first control pins 3012 and a voltage source Vcc.
The ECC 301 is configured to compare each working voltage with an associated standard voltage range, which can be prestored in the ECC 301. If any of the working voltages is below or above the associated standard range, the working voltage is regarded as abnormal, and the ECC 301 outputs a first abnormal signal such as a logic-high level to the enable pin ENABLE via the corresponding first control pin 3012 to disable the voltage chip 101 which provides the abnormal working voltage. The ECC 301 also generates a second abnormal signal such as a logic-low level to the power button pin PWRBTN# of the Southbridge 201 via the second control pin 3013 to turn off the electronic device 1. The ECC 301 further outputs a third abnormal signal such as a logic low level to turn on the indicator 3022 via the corresponding third control pin 3014 associated with the detecting pin 3011 which detects the abnormal working voltage.
Particular embodiments are shown here and described by way of illustration only. The principles and the features of the present disclosure may be employed in various and numerous embodiments thereof without departing from the scope of the disclosure as claimed. The above-described embodiments illustrate the scope of the disclosure but do not restrict the scope of the disclosure.
Number | Date | Country | Kind |
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2012105520662 | Dec 2012 | CN | national |