GENERAL DESCRIPTION
The OQ2538HP is a limiting amplifier IC intended for use as the main amplifier in 2.5 Gbits/s Non-Return to Zero (NRZ) transmission systems (SDH/SONET).
Comprised of four amplifier stages with a total gain of 48.5 dB, it provides for a wide input signal dynamic range at a constant CML-compatible output level.
Two level-detection circuits are provided for monitoring AGC and LOS input signal levels. An internal automatic offset compensation circuit eliminates offset in the amplifier chain.

FEATURES
• Differential 100 Ω outputs for direct connection to Current-Mode Logic (CML) inputs
• Wide bandwidth (3 GHz)
• 48.5 dB limiting gain
• Noise figure typically 11 dB
• Automatic offset compensation
• Input level-detection circuits for Automatic Gain Control (AGC) and Loss Of Signal (LOS) detection
• Low power dissipation (typically 270 mW)
• Single −4.5 V supply voltage
• Low cost LQFP48 plastic package.

APPLICATIONS
• Main amplifier in Synchronous Digital Hierarchy (SDH) and Synchronous Optical Network (SONET) systems for short, medium and long haul optical transmission
• Level detector for laser diode control loops
• Wideband RF gain block with internal level detectors.