ADN8820*

The ADN8820 is a versatile Continuous Wave (CW) and EDFA  laser diode driver and controller.  It provides a low noise and  precise current control for driving a source or pump laser diode.The ADN8820 has a high speed closed-loop control, making it suitable for add/drop applications in telecommunication
systems.  It has a low-current shutdown mode and a soft-start feature to minimize power supply bounce on start-up. Protection circuitry is built into the device.  The protection limits are easily adjustable and are used to set maximum output current and voltage, optical output power, EDFA gain, and pump or CW laser power.

The output stage consists of a high-efficiency PWM amplifier in parallel with a high-speed linear amplifier.  This provides the fastest settling time response along with the lowest power and heat dissipation.  A pair of external MOSFETs on the PWM amplifier provide output currents of up to 5A. Three low-bias current TIAs are built-in.  These allow amplification for the laser back-facet photodiode and EDFA input and output photodiodes.  For CW laser applications, the two unused TIAs can be used for etalon photodiode amplification, allowing continuous wavelength monitoring.  The ADN8820 is available in a 7 x 7 mm lead-frame chip scale package (LFCSP) with a package height of less than 1 mm.