| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a drive device capable of preventing breakdown of oscillators, as well as, shortening the warm-up time of oscillation, without causing circuit dimensions to increase, and to provide a physical quantity measuring device and an electronic device that use the device. <P>SOLUTION: The oscillation drive circuit 10 includes a gain control amplifier 20 that controls the oscillation amplitude in an oscillation loop for exciting the drive oscillation to an oscillator 12, and a comparator 50 that forms a reference signal for synchronous detection, based on the signal inside the oscillation loop. The oscillation drive circuit 10 uses the output from the comparator 50, to excite the gain in the oscillation loop generated by the oscillator 12 and the comparator 50, in a state of being larger than 1, followed by controlling of the oscillation amplitude in the oscillation loop, generated from the oscillator 12 and the gain control amplifier 20 to excite the drive oscillation to the oscillator 12. The comparator 50 includes output current-limiting function. <P>COPYRIGHT: (C)2008,JPO&INPIT |
