But back onto my original question: What is the formula for
determining current draw of a PWM circuit? For example, If I was
using PWM on an LED, with the PWM Frequency at 1KHz and it's
duty cycle at 50%, what is the current draw? Generally, it's
quite straightforward to calculate the average current draw, as
it is just the PWM percentage of the max. current. At 50% duty
cycle it's half, at 10% it's 10% and so on, but... It still
needs to be able to handle the max. current. A regular 20mA LED
can be used with that "formula", increasing the current, but
don't go below 2% duty cycle (with an average draw of 20mA, i.e.
1A pulses), as the bonding wires will either melt or rip off of
the crystal with too high currents, even if the average is low.
The IXDN404PI is a MOSFET driver, not a motor driver and the 4A
will only be sustained some tens of ns and only with a large
enough potential. The max. peak pulse current is very dependant
on the voltage potential (in all drivers). At 1 kHz, the chip
won't be able to sust