Functional Description
The LG1605DXB is a GaAs wideband limiting amplifier with differential inputs and outputs that provides 28 dB of gain (34 dB differential) and 3 GHz of bandwidth in a 50 Ω environment (Figure 1 shows the block diagram). At low input levels, below 10 mV to 20 mV, the circuit behaves as a linear amplifier. At higher levels, the device goes smoothly into limiting. The device matches the performance of an AGC amplifier but shows none of the AGC bouncing and attack characteristics.

Features
■ 28 dB gain, 34 dB differential
■ Large dynamic range: >60 dB
■ Wideband response: 8 kHz to 3 GHz
■ Extremely low ±4 ps delay skew across input range
■ Complementary 50 Ω I/Os
■ Surface-mount package
■ Standard ECL supply (400 mW)

Applications
■ Data/clock main amplifier SONET/SDH OC-48/ STM-16 transmission systems, DWDM systems
■ Digital video transmission
■ Interface between 1319 receiver and LG1600 clock and data regenerator
■ High-speed comparator