A Very High-Frequency Transistor-Only Linear Tunable Companding Current-Mode Integrator
A low-distortion tunable transistor-only integrator suitable for applications in the frequency range approaching the f T of transistors is presented. The circuit is a modified version of the recently introduced companding current-mode integrator utilizing the non-linear base-emitter diffusion capacitance of the BJT. A first-order approximation of the circuit characteristics is explained, followed by a brief discussion on the departure from ideal characteristics due to transistor nonidealities. Experimental and simulated results of practical integrators are given to verify the feasibility of the proposed modified circuit.
KeywordsCollector Current Analog Integrate Circuit Base Terminal Unity Gain Frequency Balance Voltage
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