AD807A-155BRZ (ANALOG DEVICES)

The AD807A-155BRZ is a Fibre Optic Receiver with quantize and clock recovery and data retiming. The AD807 provides the receiver functions of data quantization, signal level detect, clock recovery and data retiming for 155Mbps NRZ data. The device, together with a PIN diode/preamplifier combination, can be used for a highly integrated, low power SONET OC-3 or SDH STM-1 fibre optic receiver. The receiver front end signal level detect circuit indicates when the input signal level has fallen below user adjustable threshold. The threshold is set with a single external resistor. The signal level detect circuit 3dB optical hysteresis prevents chatter at the signal level detect output. The PLL has a factory-trimmed VCO centre frequency and a frequency acquisition control loop that combine to guarantee frequency acquisition without false lock. This eliminates a reliance on external components such as a crystal or a SAW filter, to aid frequency acquisition.