Programmable signal amplitude control circuits
First Claim
1. A circuit for providing an output signal of controllable amplitude responsive to the data contained in at least one externally-provided digital control signal, comprising:
- oscillator means for providing a periodic waveform having a selected frequency and a substantially constant amplitude;
an operational amplifier having an inverting input, a non-inverting input and an output;
first voltage divider means for providing the output waveform of said oscillator means to a selected one of said operational amplifier inverting and non-inverting inputs with an amplitude selected from a first plurality of selectable values, each less than the substantially constant amplitude of the oscillator means output waveform;
second voltage divider means coupled to at least said operational amplifier output and a remaining one of said inverting and non-inverting inputs, for controlling the gain of said operational amplifier to said signal from said first voltage divider means, to a selected one of a second plurality of selectable values;
means coupled to at least one of said first and second voltage divider means for controllably switching the values thereof responsive to said at least one control signal; and
a circuit output terminal coupled to said operational amplifier output, at which appears said circuit output signal with the frequency of said oscillator means output waveform and an amplitude controlled by the selected one of the first and second voltage divider means values.
1 Assignment
0 Petitions
Accused Products
Abstract
A circuit, for providing a periodic signal of programmably controllable amplitude, includes an oscillator having a substantially constant amplitude signal of desired frequency and waveform at an output thereof connected to the input of a first programmable voltage divider having its output connected to one input of an operational amplifier. The remaining operational amplifier input is connected to the output thereof via a second programmable voltage divider used as a programmably controllable feedback network. The operational amplifier output signal amplitude may be controlled by external data signals to values less than, equal to, and greater than, the substantially constant oscillator waveform amplitude. Both computer and hard-wired circuitry for controlling the output signal are disclosed. An isolation-and-rectification network may be used to recover a D.C. voltage of programmably controlled amplitude.
-
Citations
15 Claims
-
1. A circuit for providing an output signal of controllable amplitude responsive to the data contained in at least one externally-provided digital control signal, comprising:
-
oscillator means for providing a periodic waveform having a selected frequency and a substantially constant amplitude; an operational amplifier having an inverting input, a non-inverting input and an output; first voltage divider means for providing the output waveform of said oscillator means to a selected one of said operational amplifier inverting and non-inverting inputs with an amplitude selected from a first plurality of selectable values, each less than the substantially constant amplitude of the oscillator means output waveform; second voltage divider means coupled to at least said operational amplifier output and a remaining one of said inverting and non-inverting inputs, for controlling the gain of said operational amplifier to said signal from said first voltage divider means, to a selected one of a second plurality of selectable values; means coupled to at least one of said first and second voltage divider means for controllably switching the values thereof responsive to said at least one control signal; and a circuit output terminal coupled to said operational amplifier output, at which appears said circuit output signal with the frequency of said oscillator means output waveform and an amplitude controlled by the selected one of the first and second voltage divider means values. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
Specification