Monolithic oscillator utilizing frequency-locked loop feedback network
First Claim
1. A monolithic oscillator comprising:
- a crystal-less oscillator for generating a first signal having a select frequency;
said crystal-less oscillator including a frequency-lock feedback loop for stabilizing the frequency of said first signal, said frequency-lock feedback loop including a frequency-controlled resistor;
an input for receiving an external reference signal; and
a switching device coupled to said crystal-less oscillator for receiving said first signal and said switching device coupled to said input for receiving said reference signal, said switching device switchable to output at least one of said first signal and said reference signal.
2 Assignments
0 Petitions
Accused Products
Abstract
A monolithic oscillator having dual programmable fixed frequency outputs includes crystal-less oscillator circuitry utilizing frequency-locked feedback to generate ai signal having a select frequency, the frequency being stabilized over temperature and voltage by compensation circuitry associated with the crystal-less oscillator circuitry. A programmable prescaler is coupled to the crystal-less oscillator circuitry for varying the frequency of the signal generated by the crystal-less oscillator circuitry by a select amount. The monolithic oscillator further includes inputs for receiving an external signal, such as an external reference signal, or for connection to a crystal for providing an alternative frequency reference. A multiplexer is used to select either the external signal (or crystal) or the signal from the crystal-less oscillator circuitry to be used for the output signal. Monolithic oscillator further includes a programmable frequency divider coupled to the multiplexer to vary the frequency of the signal from the multiplexer by a select amount to one of the dual outputs. The other output being used as a reference output.
92 Citations
17 Claims
-
1. A monolithic oscillator comprising:
-
a crystal-less oscillator for generating a first signal having a select frequency; said crystal-less oscillator including a frequency-lock feedback loop for stabilizing the frequency of said first signal, said frequency-lock feedback loop including a frequency-controlled resistor; an input for receiving an external reference signal; and a switching device coupled to said crystal-less oscillator for receiving said first signal and said switching device coupled to said input for receiving said reference signal, said switching device switchable to output at least one of said first signal and said reference signal. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A monolithic crystal-less oscillator device comprising:
-
crystal-less oscillator circuitry for generating a first signal having a select frequency with an approximate maximum 1% variation over a select temperature range; said crystal-less oscillator device including a frequency-lock feedback loop including a frequency-controlled resistor; an input for receiving a second signal; and a switching device coupled to said oscillator circuitry for receiving said first signal and said switching device coupled to said input for receiving said second signal, said switching device switchable to output at least one of said first signal and said second signal. - View Dependent Claims (9, 10, 11, 12)
-
-
13. A programmable oscillator device comprising:
-
a crystal-less oscillator for generating a first signal having selected frequency, said crystal-less oscillator including frequency-locked feedback for stabilizing the frequency of said first signal, said frequency-lock feedback loop including a frequency-controlled resistor; a first input for receiving a second signal; a switching device coupled to said programmable prescaler and further coupled to said first input, said switching device switchable to output one of said first signal and said second signal; and a programmable prescaler coupled to said crystal-less oscillator varying the frequency of said first signal by a selected amount. - View Dependent Claims (14, 15, 16, 17)
-
Specification