ZL40539

The ZL40539 is a high performance laser diode driver capable of driving two separate cathode grounded laser diodes (e.g., 650 nm and 780 nm laser diodes).

The ZL40539 contains a 150 mA low noise read channel (ChR), and three >450 mA write channels (Ch2, Ch3 and Ch4). Each channel amplifies the positive current supplied at its reference input (INR, IN2, IN3, IN4) by a fixed factor of 100, 250, 150 and 100 respectively.

The ZL40539 is enabled with a High level applied to the Enable Pin. The read channel is activated by applying a 'Low' signal to the ENRB pin. Each fast write channel can be enabled by applying a positive voltage difference between the enable pins (EN2P, EN2N), (EN3P, EN3N) and (EN4P, EN4N). The output currents of the four channels are summed together and output as a composite signal at either OUTA (if SELA select is 'High') or OUTB (if SELA select is 'Low'). This provides the ability to drive two different laser diodes with just one ZL40539.

Voltage control of the channel reference inputs (INR, IN2, IN3 and IN4) can be achieved by using an external resistor in series with the reference channel input to convert a given reference potential to an input current.  

The ZL40539 is provided for the reduction of laser mode hopping noise. The oscillator is enabled if OSCEN = 'High', and its output signal is added to the appropriate current output (OUTA, if SELA select is 'High', or OUTB, if SELA select is 'Low'). The ZL40539 is set by external resistors from RSA or RSB to GND. Its frequency is set by an external resistor RFA or RFB to GND. RFA and RSA are selected when SELA = 'High' and RFB and RSB when SELA = 'Low'