ADN2860 datasheet(19/20 Pages) AD

19 / 20 page

ADN2860

Rev. A | Page 19 of 20

APPLICATIONS

LASER DIODE DRIVER (LDD) CALIBRATION

The ADN2860 can be used with any laser diode driver. Its high

resolution, compact footprint, and superior temperature drift

characteristics make it ideal for optical parameter setting.

The ADN2841 is a 2.7 Gbps laser diode driver that uses a

unique control algorithm to manage both the laser average

power and extinction ratio after initial factory calibration. It

stabilizes the laser data transmission by continuously monitoring

its optical power and by correcting the variations caused by

temperature and the laser degradation over time. In the

ADN2841, the IMPD monitors the laser diode current. Through

its dual-loop power and extinction ratio control, calibrated by

the ADN2860, the internal driver controls the bias current, IBIAS,

and, consequently, the average power. It also regulates the

modulation current, IMODP, by changing the modulation current

linearly with slope efficiency. Any changes in the laser threshold

current or slope efficiency are, therefore, compensated. As a

result, this optical supervisory system minimizes the laser

characterization efforts, enabling designers to apply comparable

lasers from multiple sources.

ADN2860

ADN2841

SDA

SCL

PSET

ERSET

ASET

VCC

Figure 33. Optical Supervisory System

ADN2860 Datasheet(PDF) 19 Page - Analog Devices