Automatic frequency compensation for pulse width modulated RF level control
First Claim
Patent Images
1. A system for automatically allocating to switching devices an on-time that is proportional to a cycle time, comprising:
- a voltage controlled oscillator configured to receive a tune voltage and configured to output a first signal having a frequency that corresponds to the tune voltage;
a charge accumulating circuit;
a voltage controlled current source configured to receive the tune voltage or a scaled tune voltage and configured to charge the charge accumulating circuit by outputting a current that corresponds to the received tune voltage or the received scaled tune voltage;
a comparator configured to generate a second signal by comparing a voltage of the charge accumulating circuit to a pre-determined set point; and
a circuit configured to receive the first signal and the second signal and configured to output a third signal that is a function of the first signal and the second signal,wherein the output of said circuit is coupled to the switching devices.
2 Assignments
0 Petitions
Accused Products
Abstract
Preferred embodiments of the present invention provide systems and methods that automatically correct the desired on-time of switching elements as the resonant frequency changes, so as to maintain the correct proportional value.
-
Citations
14 Claims
-
1. A system for automatically allocating to switching devices an on-time that is proportional to a cycle time, comprising:
-
a voltage controlled oscillator configured to receive a tune voltage and configured to output a first signal having a frequency that corresponds to the tune voltage; a charge accumulating circuit; a voltage controlled current source configured to receive the tune voltage or a scaled tune voltage and configured to charge the charge accumulating circuit by outputting a current that corresponds to the received tune voltage or the received scaled tune voltage; a comparator configured to generate a second signal by comparing a voltage of the charge accumulating circuit to a pre-determined set point; and a circuit configured to receive the first signal and the second signal and configured to output a third signal that is a function of the first signal and the second signal, wherein the output of said circuit is coupled to the switching devices. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method for automatically allocating to switching devices an on-time that is proportional to a cycle time, comprising:
-
producing a tune voltage; producing a first signal having a frequency that is dependent on the tune voltage; charging a charge accumulating circuit using the tune voltage or a scaled tune voltage; producing a second signal, wherein the step of producing the second signal comprises comparing a voltage of the charge accumulating circuit to a pre-determined set point; using the second signal to gate the first signal to the switching devices. - View Dependent Claims (9, 10, 11, 12, 13, 14)
-
Specification