Frequency Controller for a Monolithic Clock Generator and Timing/Frequency Reference

• US 20090167451A1
• Filed: 10/24/2008
• Published: 07/02/2009
• Est. Priority Date: 03/22/2004
• Status: Active Grant

• Current Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Original Assignee: Mobius Microsystems, Inc. (Renesas Electronics Corporation)
• Inventors: McCorquodale, Michael Shannon, Pernia, Scott Michael, Kubba, Sundus
• Granted Patent: US 7,786,812 B2
• Time in Patent Office: Days
• US Class Current: 331/176
• CPC Class Codes: H03B 2201/025 the means being an electronic switch for switching in or out oscillator elements
• CPC Class Codes: H03B 5/06 Modifications of generator to ensure starting of oscillations
• CPC Class Codes: H03B 5/1212 the amplifier comprising a pair of transistors, wherein an output terminal of each being connected to an input terminal of the other, e.g. a cross coupled pair
• CPC Class Codes: H03B 5/1228 the amplifier comprising one or more field effect transistors
• CPC Class Codes: H03B 5/124 the means comprising a voltage dependent capacitance
• CPC Class Codes: H03L 1/022 by indirect stabilisation, i.e. by generating an electrical correction signal which is a function of the temperature H03L1/021 takes precedence
• CPC Class Codes: H03L 3/00 Starting of generators
• CPC Class Codes: H03L 7/08 Details of the phase-locked loop
• CPC Class Codes: H03L 7/099 concerning mainly the controlled oscillator of the loop

Abstract

In various embodiments, the invention provides a frequency controller to control and provide a stable resonant frequency of a clock generator and/or a timing and frequency reference. Such stability is provided over variations in a selected parameter such as temperature and fabrication process variations. The various apparatus embodiments include a sensor adapted to provide a signal in response to at least one parameter of a plurality of parameters; and a frequency controller adapted to modify the resonant frequency in response to the second signal. In exemplary embodiments, the sensor is implemented as a current source responsive to temperature fluctuations, and the frequency controller is implemented as a plurality of controlled reactance modules which are selectively couplable to the resonator or to one or more control voltages. The controlled reactance modules may include fixed or variable capacitances or inductances, and may be binary weighted. Arrays of resistive modules are also provided, to generate one or more control voltages.

Claims