Vol.12, No.3 (1999) 57-63

SIMULATION OF TIME-DELAY EFFECTS IN ULTRA-HIGH SPEED AMPLIFIERS WITH NEGATIVE FEEDBACK

Gerd Nowack

Abstract The paper describes the simulation of delay times of high speed amplifiers in microstructures. Beyond the current standard of about 10 GB/s ringing and instability-problems increase in data amplifiers with an negative feedback within a stage. There are three causes for instability of the closed loop gain: (1) a not real feedback gain by the combine parasitic effects of line inductances and stray capacitances (2) too many poles (n) of the inner gain and (3) too large delay times. Let us assume: n=1 and concentrate on time delays. Results will be given in the case of unity-gain-amplifier and current-to-voltage converter with an inner transistor amplification of 10 and cut-off frequency of 10 GHz.

Key words: High speed amplifier, negative feedback amplifier.

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