Frequency synthesizer with digitally-controlled oscillator

A frequency synthesizer comprising:

• a digitally controlled oscillator, including a plurality of switched capacitors;
• and
• control circuitry for selectively enabling and disabling said capacitors, comprising:
• circuitry for tuning said digitally controlled oscillator to a selected frequency by enabling and disabling capacitors in a first set;
• and
• circuitry for modulating said digitally controlled oscillator by enabling and disabling capacitors in a second set.

A frequency synthesizer comprising:

• a digitally controlled oscillator, including a first set of switched capacitors and a second set of switched capacitors, where said second set of switched capacitors are in a physically separate area from said first set of switched capacitors;
• control circuitry for selectively enabling and disabling said capacitors responsive to an oscillator tuning word, comprising:
• first tracking circuitry for enabling and disabling capacitors responsive to an first portion of said oscillator tuning word and a first clock;
• second tracking circuitry for enabling and disabling capacitors responsive to a second portion of said oscillator tuning word and a second clock, wherein said second clock is significantly faster than said first clock.