| 摘要 |
An integratable temperature-stable voltage controlled capacitor circuit comprising a variable gain current amplifier connected in parallel and between a reference capacitor and an input-output port. The current amplifier reproduces the current from the reference capacitor, amplifies it, and then adds it in phase to the original current at the input/output port. The equivalent capacitance realized at the input/output port is a linear function of the current amplification and the applied control voltage. The magnitude of the current amplification is determined by a ratio of at least two bias currents applied to the amplifier from two different current sources. Since the gain is dependent on a ratio of bias currents and since temperature affects the bias currents equally when the voltage variable capacitor circuit is integrated on a single chip, this design provides for greater temperature stability.
|
