| 摘要 |
PURPOSE:To attain stable operation against external environment, by providing additionally a capacitor preventing bias fluctuation of an inverting amplifier and a high resistor for DC potential stabilization. CONSTITUTION:A bias resistor RB is provided between input and output terminals of the inverting amplifier A. A capacitor C1 to prevent the fluctuation of a bias point due to a leakage current at an external terminal P1 is provided between an input terminal of the amplifier A and the external terminal P1. A high resistance R1 is provided between the terminal P1 and ground to prevent a DC potential at the terminal P1 from being unstable because of the capacitor C1. Further, capacitors CG, CD, and a crystal oscillator X are provided between the terminals P1 and P2. The circuit is operated stably against external environment such as moisture through the circuit formation above. Further, similar effect is attained by providing the high resistor R1 in parallel with the capacitor C1. |
