Hello there. I`m new here and i was wondering if i can get some help.
I want to make a programmable current source, so i can control the current through a LED. The current will be controlled with an Arduino (via Arduino ID). Until now i have this in my mind:
The Arduino will generate a PWM that will be filtered with a low pass filter. The voltage resulted will be added at the PLUS terminal of an OP-AMP that controls the gate of a N-MOSFET transistor. The schematic that i think it works, of the op-amp and the transistor, is this one:
The current through the LED should be between 10mA and 100mA (add or give). The problem i encounter is what op-amp should i use, what nmosfet transistor (probably one with a low Id current), what should VDD be...
Feel free to come with ideas (simple ones), and provide me info to understand them. I'll try my best to understand them asap, and come with questions if there are any problems.
Thanks guys!
I want to make a programmable current source, so i can control the current through a LED. The current will be controlled with an Arduino (via Arduino ID). Until now i have this in my mind:
The Arduino will generate a PWM that will be filtered with a low pass filter. The voltage resulted will be added at the PLUS terminal of an OP-AMP that controls the gate of a N-MOSFET transistor. The schematic that i think it works, of the op-amp and the transistor, is this one:
The current through the LED should be between 10mA and 100mA (add or give). The problem i encounter is what op-amp should i use, what nmosfet transistor (probably one with a low Id current), what should VDD be...
Feel free to come with ideas (simple ones), and provide me info to understand them. I'll try my best to understand them asap, and come with questions if there are any problems.
Thanks guys!