| 摘要 |
PURPOSE:To simplify circuit constitution of a C-MOS quartz oscillating circuit and to reduce its power consumption, and to stabilize oscillation frequency against variations in power voltage, by adding a constant current circuit to the C-MOS quartz oscillating circuit. CONSTITUTION:A current Is generated through the oscillating operation of a C- MOS oscillating circuit 10 is equal to K5 (VGSQ5-VTNQ5)<2>, where K5 is the design constant of an MOS trasistor (TR) Q5, VGAQ5 is the gate-source voltage of the TRQ5, and VTNQ5 is the threshold voltage of the TRQ5. The current Is, therefore, contains no component of a power voltage VDD and, even if VDD has a drift, no influence is affected to it. Further, the VGSQ5 is a constant component determined by the process of the TR and it is made constant by a reference voltage generating circuit 11a to make the current Is constant. Therefore, the Is can be regulated to a constant current through the Q5 and the power consumption of the circuit is reduced. |
