Avalanche Photodiode Controller Fits In Small Optical Modules

Combining avalanche photodiode (APD) bias control and current monitoring on a single chip, the ADL5317 is intended for space-constrained optical transceiver modules. It is packaged in a 3 mm x 3 mm LFCSP (lead frame chip-scale package). For optical networks that need to ensure the responsivity of a temperature-sensitive APD, the device accurately sets the bias voltage over a range of 6V to 72V while simultaneously measuring current over a 6-decade range. For an APD to work accurately in receiver designs, continuous voltage correction and bias control are required. The 3V linear bias-control interface allows the use of a fixed high-voltage switcher, which lowers the supply decoupling and low-pass filtering requirements of traditional APD biasing designs that are prone to power supply switching noise. The device supports optical networks operating at 10 Gb/s and above. Over-current protection and over-temperature shutdown protect the device from damage. Price is $4.10 each/1,000. ANALOG DEVICES INC., Norwood, MA. (800) 262-5643.