1. Field of Invention
The present invention relates to the technology of an oscillating circuit having a semiconductor device.
2. Description of Related Art
Currently, MOS transistors are widely used in semiconductor devices, such as integrated circuits. A circuit inside a semiconductor device operates in response to a received clock signal. Accordingly, a quartz crystal oscillator is generally provided outside a semiconductor device, while an oscillating circuit including a quartz crystal oscillator is formed both inside and outside such a semiconductor device.
FIG. 6 is a diagram illustrating a basic configuration of a conventional oscillating circuit 900. As shown in the diagram, the oscillating circuit 900 includes a quartz crystal oscillator 910, a feedback resistor 920 connected in parallel to the quartz crystal oscillator, an inverting amplifier 960 connected in parallel to the quartz crystal oscillator, and a buffer circuit 970 connected to the output terminal of the inverting amplifier. In FIG. 6, the quartz crystal oscillator 910 and the feedback resistor 920 are provided outside a semiconductor device 950. Meanwhile, the inverting amplifier 960 and the buffer circuit 970 are provided inside the semiconductor device 950 and each comprise an MOS transistor.
USPTO Backgrounds
USPTO Backgrounds