DC42 said:I've done some sums, and from the datasheet I think the PWM frequency of the TLC5947 should be around 1kHz (based on 4MHz nominal internal clock and 4096 clocks per PWM cycle). If you use a 100uF decoupling capacitor, that will give an impedance of 1.6 ohms to ground. To get a 10-fold reduction in the amplitude of the unwanted signal, the impedance of the inductor should be 16 ohms, which implies an inductance of about 3.3mH
To get a 10-fold reduction in the amplitude of the unwanted signal, the impedance of the inductor should be 16 ohms
You really need to learn the SI prefixes.
Will the inductor have any DC flowing thru it?
The henry (lower case h), symbol "H" (upper case), is that inductance thatgenerates 1 volt when the current changes uniformly at 1 amp per second.Thus 1uH needs the current to be changing at 1 amp per microsecond to generate1 volt. (or equivalently generates 1uV when current changes at 1A/s)