Interstage Current Limiter Circuit for Extending the Dynamic Range of a Fiber-Optic Receiver
Original Publication Date: 1985-Jun-01
Included in the Prior Art Database: 2005-Feb-18
In order to solve a pulse-width distortion problem in a fiber-optic receiver, used in a data bus application, the normal two level signal at the output of the preamplifier is passively differentiated by an RC circuit, as shown in the diagram. The minimum signal at B is conventionally amplified by a post amplifier whose output is fed to a comparator whose threshold is set for the minimum expected signal. The comparator output is a logic level signal which is the reconstruction of the signal into the preamplifier. Larger signals cause the crossing of the threshold earlier in time, but the reconstructed pulse widths are not distorted.