公开(公告)号：JPH11103239A

公开(公告)日：1999-04-13

申请号：JP15042898

申请日：1998-05-29

Applicant: ST MICROELECTRON INC

Inventor： DANSTROM ERIC J ,  BUCHANAN JOHN

IPC: G06F1/04 ,  A61M5/24 ,  G01P3/48 ,  H03K3/011 ,  H03K3/017 ,  H03K3/0231 ,  H03K3/03

Abstract: PROBLEM TO BE SOLVED: To provide a precise oscillator capable of reducing the complexity of its circuit without requiring a precise crystal and to provide operation method therefor. SOLUTION: The precise oscillator 30' is provided with a capacitor, a charging current source 90, a discharging current source 91, a switch 93 for alternately connecting the capacitor to respective current sources 90, 91, and a hysteresis comparator 95 connected to the capacitor and capacitor of generating oscillation in response to the charge and discharge of the capacitor. Preferably a duty cycle controller 100 is connected at least to one of the current sources 90, 91 and steps up the duty cycle of an oscillation signal by setting up a charging current and/or a discharging current and the ratio of the charging current to the discharging current.