This application note describes the 32-lead ADN2848 laser diode driver Rev. A1 evaluation kit. The evaluation kit is a demonstration board that provides ac-coupled optical evaluation of the ADN2848. This document describes how to configure the board in order to operate this part optically.
The ADN2848 is a 3 V dual-loop 50 Mbps to 1.25 Gbps laser diode driver. To use the board in an optical configuration, a suitable laser diode driver must be soldered onto the board. The monitor photodiode, MPD, current is fed into the ADN2848 to control the average power and extinction ratio. The ADN2848 uses automatic power control, APC, to maintain a constant average power over time and temperature. The ADN2848 also uses closed-loop extinction ratio control to allow optimum setting of extinction ratio for every device. This board is configured for lasers in miniDIL packages only. LEDs for Power Supply, DEGRADE, and FAIL are made available for monitoring purposes. Power to the ADN2848 evaluation circuitry is only –3.3 V.