The ADN2890 is a high gain, limiting amplifier optimized for use in SONET, Gigabit Ethernet (GbE), and Fibre Channel optical receivers that accept input levels of up to 2.0 V p-p differential and have 3 mV p-p differential input sensitivity. The ADN2890 provides the receiver functions of quantization and loss of signal (LOS) detection. The ADN2890 can easily operate at up to 3.2 Gb/s to support LX4 transceivers. The limiting amplifier also measures average received power based on a direct measurement of the photodiode current with better than 1 dB of accuracy over the entire input range of the receiver. This eliminates the need for external average Rx power detection circuitry in SFF-8472 compliant optical transceivers.