Title:
VOLTAGE CONTROL VARIABLE OSCILLATOR ESPECIALLY FOR PHASE SYNCHRONIZING LOOP
Document Type and Number:
Japanese Patent JPH0376316
Kind Code:
A
Abstract:
PURPOSE: To secure the stable signals for the frequency and the peak-to-peak value when the temperature and the process parameter are changed and to facilitate the integration of a phase-locked loop by connecting one of both terminals of a VCO to one of output terminals and adding a capacitor to the other terminal of the VCO. CONSTITUTION: An angular velocity ω is calculated by an expression I, where C, L and K show the capacity, the inductance and a fraction of a potential difference respectively. The operating frequency of an oscillator can be changed with change of the inductance K. The external oscillation frequency control voltage VC is generated in a differential step formed by the transistors TR T5 and T6 . Each of both TR T5 and T6 has an emitter resistor to receive the reference voltage Vref and the voltage VC on a base and to keep the peak-to- peak value of an oscillation constant via a block 2. The load impedance GT is calculated by an expression II and its absolute value is reduced with reduction of the operating frequency of the oscillator. The transconductance gain is increased with increase of the differential bias current IO of the oscillator. Thus, the total circuit loop gain is kept constant.
Inventors:
JIYORUJIYO BETSUTEI
MAURITSUIO TSUTSUFUAADA
MAURITSUIO TSUTSUFUAADA
Application Number:
JP20749190A
Publication Date:
April 02, 1991
Filing Date:
August 03, 1990
Export Citation:
Assignee:
SGS THOMSON MICROELECTRONICS
International Classes:
H03B5/12; H03L7/099; (IPC1-7): H03B5/12; H03L7/099
Attorney, Agent or Firm:
Fukami Hisaro (2 outside)
Next Patent: JPH0376317