Title:
自動調整発振器
Document Type and Number:
Japanese Patent JP5461852
Kind Code:
B2
Abstract:
A self-calibrating oscillator that increases the output frequency accuracy without using a charge pump includes an oscillation circuit, a pulse counter, a charging circuit, a reset circuit, a calibration circuit, and a timing control unit. The pulse counter counts a pulse signal having frequency f0 from the oscillation circuit based on a count start signal provided from the timing control unit, while providing an output signal to the charging circuit. The charging circuit connects a constant current source and capacitor when provided with the output signal to raise the voltage at the connection node. The calibration circuit provides the oscillation circuit with a calibration value for increasing the frequency if the voltage when the output of the output signal ends is higher than a high potential reference voltage and provides a calibration value for lowering the frequency if this voltage is lower than a low potential reference voltage.
Inventors:
Eiji Shikata
Application Number:
JP2009051205A
Publication Date:
April 02, 2014
Filing Date:
March 04, 2009
Export Citation:
Assignee:
Freescale Semiconductor, Inc.
International Classes:
H03L7/00
Domestic Patent References:
| JP2002300027A | ||||
| JP57110967A | ||||
| JP2007318760A | ||||
| JP2006086997A | ||||
| JP2000048113A | ||||
| JP61075271A |
Attorney, Agent or Firm:
Mamoru Kuwagaki