The high laser power of laser pointer has the different application

The high laser power of laser pointer has the different application .
IGBT in the switch state, by the DSP to control the opening and shutdown time. When the IGBT is turned on, the voltage on the input filter capacitor through IGBT increase in the inductor L and capacitor C3 at both ends of the inductor current can not be mutation, the inductor current is only a linear increase; when the IGBT is off, still not due to the inductor L current mutation reverse the induced voltage on the inductor, the inductor current decreases linearly, while the diode Diode conduction, the continued circulation of the inductor L current road, re-open until the next cycle of IGBT. All kinds of laser pointer also have their own advantages and characteristics.
The inductor current down to the inductor current on a cycle of initial. Inductor current in a switching cycle, showing the triangular wave, and the initial value and end value of the inductor current is equal to the adjacent cycle. Seems greater than the switching period of time, the inductor current is approximately the same, and the average inductor current is equal to the final output current, the inductor average current is constant, we can guarantee the final output current constant. Current detection by Hall current sensor, the Hall current sensor output current sampling signal, the signal and sampling the current signal proportional to the current, this current signal through a precision resistor to ground on the measurement precision resistors voltage, can know the size of this current, in order to know the size of the real current. The customer can choose the most suitable and appropriate kind of laser pointer . 
The 10K resistor has two functions: 1. AD port input impedance decreases; 2. The release of the filter capacitor charge and electrostatic charge accumulated.If possible, the RC filter cutoff frequency should be lower than the switching frequency of 1/10, when the smoothing filter function of the RC filter circuit better. According to TI's data sheet, in 2812 AD sampling circuit accuracy is not very high, generally only 2%. AD sample software calibration software calibration accuracy can reach 0.5%. Refer to TI's application notes, design the hardware circuit of the correction required. The power of the green laser beam of laser pointer is 100mW.