Hi,
I'm designing a board where the microcontroller is supposed to drive
10 red leds and 4 optocouplers.I would like to drive the leds and the opto's without a series resistor using the PWM technique. I made some experiments and all seems to work fine in the lab.
- The supply voltage is 3.3 Volt
- The microcontroller is an ARM7 by NXP (LPC2387)
- In DC, the microcontroller's GPIO ports are able to source or sink
- The leds are driven with a duty cycle of 1/5. The average current that the leds sink is 5 mA.
- The light emitted by the leds in these condition (1/5 PWM) is more than acceptable.
Based on your experience and knowledge, what do you think about this solution?
Should I sink (the N-MOS will work) or source (I P-MOS will work) the current?
Thanks in advance for any suggestion, Enrico