# ESR Capacitor ESR - Right selection

I have a PWM signal at 100Hz ("Vg" label at circuit) with variable duty cycle (10%-90%). Because I had voltage spikes I managed to eliminate them by placed three capacitors which types and values are below. My query is if the ESR of these capacitors is right for this frequency (100Hz) that I am using and if no which value of ESR is the right?

P.S. I don't want to place ceramic capacitors because they produces an acoustic noise/buzz.

Tantalum Capacitors - Solid SMD 35volt 0.1uF 10%
T494A104K035AT
Tantalum Capacitors - Solid SMD 35V 1.0uF 10% "A"
T491A105K035AT
Tantalum Capacitors - Solid SMD 10V 10uF 10% "A"
T491A106K010AT


• I see no capacitor type/value and I see no circuit diagram that shows what you did or anything about the spikes. Ah only 14 minutes to update the info, not bad LOL but what about the circuit and spikes? – Andy aka Sep 8 '14 at 17:00
• My question is not about the spikes but for the ESR of the capacitors C1,C2,C3. – 2 X Sep 8 '14 at 17:23
• Why did you pick tantalums? – dext0rb Sep 8 '14 at 18:11
• What are LP1 and 2? I can't see that ESR matters very much here. What is that second FET doing? – George Herold Sep 8 '14 at 19:10
• LP1 and LP2 are car lamps. – 2 X Sep 9 '14 at 12:57