The advantage to this design is that the design can easily achieve the LED Current adjustment from SOC PWM signal with low pass filter. There is no need to change the current through BOM changing. This process is a smart way to use SOC to control the current. Also, this process can make a PWM dimming design to becoming an analog dimming design. The design does not have a flicker issue when video surveillance system captures the video since the design changes to analog dimming.

The disadvantage to this design is not a formal way to design a IR LED driver. The design is not wrong, but there are better options. The design needs to add extra resistor and capacitor to make the low pass filter. Also, the linearity is not easy to make a combination. Also, accuracy is not enough. Please see TI TPS92201 to address the previous issue.