| 摘要 |
PROBLEM TO BE SOLVED: To obtain a high voltage protection circuit for protecting an analog input terminal and an output terminal of an integrated circuit device from the electrostatic discharging condition. SOLUTION: A first circuit a voltage reference terminal 24, a pin 12 and a pin resistor 13 connected in series to an input terminal 14 to a function circuit. An anode of SCR 30 is connected to the input terminal 14 and a cathode thereof is connected to a voltage reference terminal. A shunt resistor 19 is connected between anode and anode gate of SCR 30, while another shunt resistor 20 is connected between a cathode and cathode gate. A zener diode 22 is also provided to set a breakdown voltage between anode gate and cathode gate of the SCR. This integrated circuit protects a device against a positive high voltage and also protects the device from a negative ESD voltage by switching the anode connection to the cathode connection. |
