Michael Frank Haight

US Patent:

47990309, Jan 17, 1989

Filed:

May 12, 1987

Appl. No.:

7/049187

Inventors:

Michael H. Haight - Plano TX
William H. Giolma - Dallas TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

H03B 508

US Classification:

331117R

Abstract:

An oscillator circuit having a coil and capacitor tank circuit, a clamp resistor connected at one end to the coil and a switch coupled to the clamp resistor and coil. The switch is operative to close in response to a first input logic clamp signal and shunt the coil with an impedance that causes the oscillation to stop quickly. In response to removal of the input logic clamp signal the tank circuit starts to oscillate from a known state. Preferably the clamp resistor has a value which equalizes the tank currents for the clamped and peak unclamped states.

US Patent:

47630868, Aug 9, 1988

Filed:

May 12, 1987

Appl. No.:

7/049186

Inventors:

Michael H. Haight - Plano TX
William H. Giolma - Dallas TX
Richard Boucher - Santa Clara CA

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

H03B 508
H03L 500

US Classification:

331109

Abstract:

A voltage controlled oscillator circuit of a type having a tank circuit for generating oscillations which includes a means for establishing a fixed bias voltage with respect to ground at a bias end of said tank circuit, means for drawing current from an a. c. end of said tank so as to control the tank gain, and an AGC capacitor. A constant current source is coupled to the AGC capacitor for supplying it with a constant charging current. Means are provided for discharging the AGC capacitor at a voltage level determined by a ratio of resistors and a transistor emitter-base ratio.