MCP1630V is PWM controller with voltage / current check, it requires a microcontroller to get the frequency reference
an if required you can even control the dimming via software. This board i built is a current control boost device i use
to drive high power LEDs. The logic runs at 5V and usually gets the regulated voltage through the micorcontroller regulator
like 7805 and so on.
Vcc input 7.5 to 18V
Max out current 1A
Max out voltage 50V
Max out power 30W
Current output is regulated between the relationship of dropped voltage of R1 & R2 intersection and the voltage drop of the shunt resistor/s
R6 & R7. That means if we whant to drive a 200mA LED and we have 0.5 volt as a shunt resistor with 200mA is V=R*I = 0.2*0.5=0.1V
Therefore the voltage across the intersection of R1 & R2 must be the same voltage, if we consider that we have 5V from the MCU in the
DIMM input we will use something like R1=200ohm & R2=10K because Vout=R1/(R1+R2)*Vin = 200/(10200)*5 = 0.098V.
The accademic formula is normally Vout=R1/(R1+R2)*Vin but in this case mi design has resistors with upside down names.