Protective circuit for semiconductor circuit

Abstract

Abstract PURPOSE:To attain a protective function without attenuating an analog signal even when the circuit is used for an external connecting terminal transmitting or receiving an analog signal value and without largely increasing chip size by constituting the protective circuit without using a series resistor. CONSTITUTION:With a capacitor 13, one terminal is connected to an input terminal 2, and the other terminal is grounded through a high resistor 14. With a MOST 12, a drain is connected to the input terminal 2 and a gate to a node between the capacitor 13 and the high resistor 14 and a source is grounded, and it emits normal threshold voltage. In the circuit, the gate voltage of the MOST 12 rises instantaneously through the capacitor 13 when high voltage is applied to the input terminal 2. Since the MOST 12 does not emit high threshold voltage as seen in conventional circuits, conductance is large, sufficient currents flow, the voltage of the input terminal 2 attenuates suddenly, and the semiconductor circuit A to be protected is protected.

Inventors

• 👤 Minoru Takeuchi
• 👤 稔 竹内

Bibliographic Details