| 摘要 |
PURPOSE: A common voltage stabilizing circuit using clamping circuit fixes a fluctuating common voltage appropriately to stabilize the common voltage. CONSTITUTION: A capacitor(C1) filters a common voltage(Vcom1) to a common voltage(Vcom2). The common voltage(Vcom2) is clamped by the amplitude of voltage of a resistor(R1). A comparator(COM) compares a voltage of the resistor(R1) inputted from a converting terminal with a reference voltage(Vref) for determining the path of a current flowing through the resistor(R1). A diode(D2) is turned-off and a diode(D1) is turned-on due to the high level signal outputted from the comparator(COM) when the reference voltage(Vref) is larger than the voltage of the resistor(R1). At this time, the current flows through the resistor(R1), the comparator(COM) and the diode(D1). The common voltage(Vcom2) is as clamped as the potential of the reference voltage(Vref). On the other hand, the comparator(COM) outputs the low level signal when the voltage of the resistor(R1) is larger than the reference voltage(Vref). At this time, the current flows through the resistor(R1) and the diodes(D2,D1). The voltage variation of the capacitor(C1) becomes the common voltage(Vcom2).
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