| 摘要 |
A malfunction prevention circuit of a backlight driving control device is provided to reset a microcomputer and protect a circuit safely in an abnormal state by detecting a variation of a checked voltage. A malfunction prevention circuit of a backlight driving control device includes a microcomputer(100), an amplifying transistor(Q1), a first AC filter capacitor(C1), a first FET(Field Effect Transistor)(Q2), a second AC filter capacitor(C3), a second FET(Q3), and a regulator(200). The microcomputer outputs a first state voltage in a normal state, and outputs a second state voltage in an abnormal state. The amplifying transistor amplifies the first state voltage and the second state voltage of the microcomputer to a predetermined level. The first AC filter capacitor passes an AC component of the first and second state voltages amplified by the amplifying transistor. The first FET is controlled by a voltage outputted from the first AC filter capacitor, and switches a predetermined constant voltage. The second AC filter capacitor passes an AC component of the constant voltage based on a switching state of the first FET. The second FET is controlled in response to an output of the second AC filter capacitor, and switches the constant voltage. The regulator controls a supply state of a driving power of the microcomputer in response to an input of the constant voltage according to the switching of the second FET. |
