Q
I'd like to use the ADN2830 for a CW laser diode power control. Laser diode andphotodiode are connected with common cathode. I'd like to have the photodiode
current monitor on pin IMPDMON so I'll connect the photodiode anode to the IMPD
pin. Has the IMPD voltage to be equal to 1.23V as for PSET pin?. Moreover I'd
like to connect diodes cathode to GND, can the ADN2830 work as current source
in this scheme?
A
ADN2830 has one on-chip APC (average power control) loop. It can accept thephotodiode anode current to PSET or IMPD pins, provided the photodiode cathode
be connected to Vcc.
ADN2830 IBIS pin is a current sink. So, it can only accept laser diode cathode
pin while the laser anode pin connected to Vcc.
If you use the right laser, ADN2830 can easily drive the laser while
compensating for the laser temperature and ageing effects.