LT3756 use Hi Side Sense.
Can it be done by low side?
because of the 100V limit, we can only operate below 100V.
while over 100V, the LT3795 is the only solution.
Why or why not use low side sense ?
Thank you for your kind assistance !
The common mode ranges of ISP/ISN for the LT3756 and LT3795 respectively are 2.9V-100V and 0V-110V as I show in the image below from the datasheets. You can put RSENSE on the bottom when you use the LT3795. That way, you can increase your output voltage as high as you like but you will not be able to use the PMOS for PWM dimming of the LED brightness or short protection - those are the only drawbacks.