LDX-3232 Modulation Bandwidth
This Tech Note provides information on the modulcation bandwidth of the LDX-3232 High Compliance Laser Diode Driver. The output of the LDX-3232 is capable of being modulated via a signal input into the front panel BNC labeled External Modulation. This feature is designed to allow output current modulation through the summing of a continously varying signal with the CW bias current. The magnitude of the additional current is proportional to the modulation voltage and the proportionality constant is called the modulation transfer function. For the LDX-3232, this transfer function is 200 mA/V in the 2 Amp range and 400 mA/V in the 4 Amp output range. The total output current may be easily determined when one remembers it is the CW bias current plus modulation current. For example, if the CW bias is set to 1000 mA with no modulation input, the output will obviously be 1000 mA.