| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress power consumption of an oscillator including a crystal oscillating circuit, a semiconductor device, an electronic apparatus, or the like as a whole. <P>SOLUTION: An oscillator comprises: a constant voltage generating circuit that includes a first constant current source for generating a first constant current and a constant voltage controlling transistor energized with the first constant current for generating a constant voltage; a crystal oscillating circuit that is oscillated and driven by the constant voltage supplied from the constant voltage generating circuit. The constant voltage has a first slope that varies in response to the first constant current in an operation guaranteed temperature range. In the crystal oscillating circuit, an oscillation stop voltage in the operation guaranteed temperature range has a second slope. The first slope is set so as to minimize a sum of current consumption of the crystal oscillating circuit that has a correlation with a difference between the first slope and the second slope and current consumption of the constant voltage generating circuit that has a correlation with a magnitude of the first constant current. The first constant current is set to a value that causes the constant voltage controlling transistor to be operated in a sub-threshold region. <P>COPYRIGHT: (C)2013,JPO&INPIT |
