公开(公告)号：ID25636A

公开(公告)日：2000-10-19

申请号：ID20001001

申请日：1998-10-06

Applicant: ERICSSON TELEFON AB L M

Inventor： GARDENFORS TORBJOM ,  BENGTSSON ERIK ,  ENSTROM HAKAN

IPC: H03B5/32 ,  H03B5/04 ,  H03B5/36 ,  H03L1/02 ,  H03L5/00

Abstract: A highly stable single chip crystal controlled oscillator with automatic gain control. An amplitude detector monitors the output of a crystal controlled oscillator amplifier and produces a feedback signal proportional to the output signal of the amplifier to ensure oscillation is induced at startup and that the amplitude of oscillation is limited to a preselected value during operation to conserve power consumption by the amplifier. The capacitor tank circuit connected to the input of the amplifier includes a voltage variable capacitor the voltage across which is initially established at manufacture to tune the oscillation frequency to a preselected value. The voltage across the voltage variable capacitor is also adjusted to compensate for temperature variations in the circuit.