| 摘要 |
Adjustable coring circuit includes linear amplifier and multistage limiting amplifier responsive to input signals from a common source. Limiting amplifier includes an input stage receiving operating current from a first current source transistor, in cascade with an output stage receiving operating current from a second current source transistor. Cored signal, corresponding to the difference between a linearly translated version of the input signals and a doubly clipped version thereof, is developed by a signal combiner responsive to outputs of both amplifiers. Base-emitter paths of the two current source transistors are connected in series across a common bias source. The base electrodes of two control transistors, of mutually opposite conductivity types, respond to variations of common coring level control voltage. Collector-emitter path of one control transistor shunts base-emitter path of first current source transistor. Emitter-collector path of other control transistor, which shunts the common bias source, is nonconducting over major portion of variation range of coring level control voltage.
|
