High-accuracy current and temperature control for laser diode using MCS-51 microcontroller

A laser controller consisting of MCS-51 microcontroller and Texas Instruments DRV592 power driver is presented.The DRV592 is a high-efficiency,high-current H-bridge ideal for driving a wide variety of the thermoelectric cooler(TEC)elements in systems powered from2.8Vto5.5V.The MCS-51 microcontroller implements a digital proportional-integral-derivative feedback controller using an analog-to-digital converter to read the thermistor,and direct output of pulse-width-modulated waveforms to the H-bridge DRV592 power amplifier.The laser controller can achieve ±0.1℃ temperature and milliampere accuracy,which is internally protected against thermal and current overloads.