Current controlled oscillator including conversion of control voltage to regular and thresholded control currents
First Claim
Patent Images
1. A voltage-controlled oscillator circuit, comprising:
- an oscillating circuit for generating an oscillatory output signal with a frequency that varies responsive to an applied control current;
main current control means for regulating said control current responsive to an applied control voltage;
a thresholding circuit with a first threshold voltage and a second threshold voltage, said first threshold voltage being higher than said second threshold voltage, for receiving said control voltage and producing a thresholded signal having two states, a first state entered when said control voltage rises past said first threshold voltage and a second state entered when said control voltage falls below said second threshold voltage; and
a constant-current circuit switched on and off by said thresholded signal, for varying said control current by adding a fixed current thereto.
2 Assignments
0 Petitions
Accused Products
Abstract
A voltage-controled oscillator circuit generates an output signal with a frequency that varies in response to a control current regulated by an applied control voltage. The voltage-controlled oscillator also thresholds the control voltage according to two different threshold voltages, producing a thresholded signal with a hysteresis characteristic. The thresholded signal switches a constant-current circuit on and off. When switched on, the constant-current adds a fixed current to the control current, thus widening the frequency range of the output signal.
-
Citations
10 Claims
-
1. A voltage-controlled oscillator circuit, comprising:
-
an oscillating circuit for generating an oscillatory output signal with a frequency that varies responsive to an applied control current; main current control means for regulating said control current responsive to an applied control voltage; a thresholding circuit with a first threshold voltage and a second threshold voltage, said first threshold voltage being higher than said second threshold voltage, for receiving said control voltage and producing a thresholded signal having two states, a first state entered when said control voltage rises past said first threshold voltage and a second state entered when said control voltage falls below said second threshold voltage; and a constant-current circuit switched on and off by said thresholded signal, for varying said control current by adding a fixed current thereto. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method of controlling a voltage controlled oscillator circuit comprising the steps of:
-
providing a control voltage; processing said control voltage in a hysteresis circuit so that in response to said control voltage rising past an upper threshold voltage, a first state is entered, and in response to said control voltage falling below a lower threshold voltage, the first state is departed; and modulating the oscillating frequency of the oscillator circuit in accordance with whether the circuit is in the first state. - View Dependent Claims (9, 10)
-
Specification