Method and circuit for an automatic, high precision frequency fine tuning

US5524289A · kind A · utility

Inventors

• Rudolf Koblitz · Planegg, DE
• Martin Rieger · Rottweil, DE
• Sabine Roth · Berlin, DE

Key dates

• Filing date: Mar 14, 1994
• Grant date: Jun 4, 1996
• Expiry date: Mar 14, 2014

Classification

• Technology area (CPC H): Electricity
• CPC primary: H03J7/04
• WIPO field: Basic communication processes
• WIPO sector: Electrical engineering

Abstract

For the purpose of a high precision frequency fine tuning, for example, to a certain television channel, an analog circuit, the frequency of which can be balanced, for example, an demodulator, is balanced in an integrated circuit with the help of a control current. The control current generated in a regulating loop is dependent on a reference frequency with the appropriate accuracy and on a reference frequency with the appropriate accuracy and on a reference capacitancy integrated on the chip. After selecting a frequency, the analog circuit is calibrated and the frequency is subsequently fine-tuned in a measuring mode. Following that, the analog circuit operates in the normal mode.