Means and method for optimizing the switching performance of power amplifiers
AssigneeMotorola, Inc.
InventorsWarren I. Schultz, Denise M. Williams
Life of this patent
Estimating the term…
Abstract
Reduced transient power dissipation and reduced variation of the transient power dissipation are obtained in high frequency power amplifiers, e.g., CRT horizontal deflection amplifiers, by sampling the amplifier output at and/or during the turning-off interval (e.g., during the storage time when transient power dissipation is still low and optionally also during turn-off when transient dissipation is large) and then, after a suitable delay, feeding back a signal proportional to the sampled output to the amplifier input driver to control the magnitude of the input drive during a subsequent amplifier-on interval. The desired delay corresponds approximately to the intervening amplifier-off interval.
Claims7
A circuit for cyclically driving a load and minimizing transient energy dissipated in the circuit, comprising:
- an amplifier having an output terminal coupled to the load and having an input terminal;
- driver means coupled to the input terminal of the amplifier for providing current thereto during a first portion of a drive cycle and receiving current therefrom during a second portion of the drive cycle;
- sampling means coupled to the output of the amplifier for measuring the output of the amplifier during a portion of the drive cycle following the first portion of the drive cycle;
- and
- regulator means coupled to the sampling means and the driver means for optimizing the current provided to the input of the amplifier during the first portion of a subsequent drive cycle in response to the output of the amplifier measured by the sampling means during the portion of the drive cycle following the first portion of the drive cycle to minimize transient energy dissipated in the circuit.
A circuit for cyclically driving a load, comprising:
- an amplifier having output terminals coupled to the load and a common terminal and having an input terminal;
- driver means including an inductor having first and second terminals wherein the first terminal is coupled to the input terminal of the amplifier for providing current thereto during a first portion of a drive cycle and receiving current therefrom during a second portion of the drive cycle, the driver means further including a transformer having primary and secondary windings, the transformer being coupled to the second terminal of the inductor and to a switch for periodically supplying current thereto;
- sampling means coupled to the output of the amplifier for measuring the output of the amplifier during a portion of the drive cycle following the first portion of the drive cycle;
- and
- regulator means coupled to the sampling means and the driver means for adjusting the amount of current provided to the input of the amplifier during the first portion of a subsequent drive cycle in response to the output of the amplifier measured by the sampling means during the portion of the drive cycle following the first portion of the drive cycle.
Dependencies are inferred from the claim text.