CIRCUIT CONFIGURATION FOR COMPENSATION OF LEAKAGE CURRENTS IN VOLTAGE-CONTROLLED OSCILLATOR OF PLL CIRCUIT

Japanese Patent JP2008271599

A

To obtain a circuit configuration for compensation of leakage currents in a voltage-controlled oscillator of a PLL circuit.

A control voltage applied to the oscillator by way of a loop filter (20)is generated by a phase detector (16) as a function of the phase difference between the phase of a reference signal and the phase of the signal outputted by a voltage-controlled oscillator (12). The oscillator (12) contains varicap diodes (28, 30) to which the control voltage is applied via a control line (34). A compensation circuit (K) provided with varicap diodes (36, 38) in the same configuration reproduces, at one of its outputs (44), the control voltage, applies it to the varicap diodes (36, 38) in the compensation circuit (K), supplies, from its other output (46), a current equal to the leakage current of the varicap diodes (36, 38). A current shunt-off branch leads from the control line (34), by way of which a current which corresponds to the current supplied by the operational amplifier (40) flows from the control line (34).

WO/2000/028665	FREQUENCY TUNING FOR RADIO TRANSCEIVERS
JPH05102780	FREQUENCY STABILIZING METHOD FOR CRYSTAL RESONATOR AND TEMPERATURE COMPENSATION CRYSTAL RESONATOR
JPH08328688	TEMPERATURE ABNORMARITY PROCESSING SYSTEM AND DATA PROCESSING UNIT HAVING TEMPERATURE ABNORMARITY PROCESSING FUNCTION

VANSELOW FRANK
CURRADI LEONARDO

JP2008170981A

November 06, 2008

June 30, 2008

Click for automatic bibliography generation  

TEXAS INSTRUMENTS DEUTSCHLAND

H03L1/02; H03B5/04; H03B5/12; H03L7/099; H03B1/00

Hideto Asamura
Hajime Asamura
Kuniaki Shimizu
Hayashi Zouzo

Previous Patent: FOLDING TYPE TERMINAL DEVICE AND DISPLAY METHOD

Next Patent: ON-BOARD STEREOPHONIC SOUND FIELD PLAYBACK APPARATUS