The AZ88943 is a limiting post amplifier usable at data rates up to 2.5Gbps. It is ideal for use as a post amplifier following a transimpedance amplifier. The AZ88943 contains a programmable signal detect function to determine when the input signal is present. This information can be used with the /EN input pin to disable the output under loss of signal conditions. The detect threshold can be set with a resistor divider between VCC and VREF. The SD output is an open drain compatible with CMOS and TTL.