| 摘要 |
PURPOSE:To decrease a resistance value of a resistor deciding an oscillating frequency by reducing a current of a reference current source by means of a current mirror circuit to use the current as a charge/discharge current of a capacitor of an oscillation circuit. CONSTITUTION:The oscillation circuit is constituted by CMOS inverters 1, 2, capacitors 5, 5' deciding the oscillation frequency, a differential amplifier circuit 10 as the reference current source, and the current mirror circuit 20. A divided voltage formed by resistors 16 and 17, i.e., a voltage at a point (a) is balanced at a voltage equal to a voltage at a point (b). A current which transistors 22 and 24 of the circuit 20 can flow is proportional to VDD/RS, where VDD is the power supply voltage and RS is a resistance value of a resistor 18. |
