DESCRIPTION

AK2570 is the monolithic CMOS LSI has the function of ‘Feed Forward Automatic Power Control (APC)’ for the Laser Diode (LD) module and maintains the emission intensity of the LD module constant with the high accuracy. For stabilizing the emission intensity of the LD module affected by the ambient temperature, AK2570 feeds the compensation voltage from the 2channels - 8bits D to A converter to control the Bias- and the Modulation- current for the LD module. The compensation voltage corresponds to the temperature characteristic data of the LD module retained in the on-chip EEPROM and the ambient temperature detected by the on-chip thermo-sensor. AK2570 outputs the alarm signal for the weakened LD emission caused by the aging degradation with comparing the alarm threshold level and the signal from the monitoring Photo Diode (PD). The data of the compensation voltage and the alarm threshold level retained in the on-chip EEPROM can be set to suit for the characteristics of each LD module.

FEATURE

· Realizing all APC function on 1 silicon chip

· Controlling the driving current (the Bias- and the Modulation- current) for the LD module

* Consisting of the 2channels - 8bits D to A converter and the Op-amp

· EEPROM (Electrically Erasable Programmable Read Only Memory)

* The Non-volatile Memory

* The memory capacity : Address 9bits ′ Data 16bits

* Retaining the data of the compensation voltage and the trimming data of the T-SENSE offset voltage and the ALM timing for each LD module

· On-chip Thermo-sensor (T-SENSE)

* Detecting the ambient temperature and converting the detected temperature to the voltage

· On-chip Alarm circuit

* Outputting the alarm signal for the weakened LD emission caused by the aging degradation

· On-chip Oscillator

· On-chip Power on reset circuit

· Serial interface

· +3.3V±10 single voltage supply

· Low power consumption (30mA [max])

· Small package (20pin - SSOP : 7.9mm ′7.4mm)