Hi All:
I'm using a 20Vds logic level MOSFet capable of about 9A to drivae a 5A 12V LED string with PWM.
Would placing a 50V, 0.1uF X7R SMD cap across the Drain/source be sufficient for bypassing any transients generated by the wiring upon switch off?
Edit: LTSPICE says no, a 1uF is required, but a freewheel diode seems best. Estimating wiring inductance at about 1 uH between LED modules with up to 50 modules.
Hi All:
I'm using a 20Vds logic level MOSFet capable of about 9A to drivae a 5A 12V LED string with PWM.
Would placing a 50V, 0.1uF X7R SMD cap across the Drain/source be sufficient for bypassing any transients generated by the wiring upon switch off?
Edit: LTSPICE says no, a 1uF is required, but a freewheel diode seems best. Estimating wiring inductance at about 1 uH between LED modules with up to 50 modules.
Just use a 10A or greater, 24V or higher Schottky diode and decouple the 12V supply line near the MOSFET with a 47UF aluminum electrolytic capacitor in parallel with a 220nF ceramic capacitor or just one 22uF ceramic capacitor. Both ceramic capacitors should be X7R and not surface mount- the bigger the better.