My class D amp

Hi Manoj,

What is the differences between EE type cores (ER-ETD-EE,etc) and toroid cores in class-d application ? because i think when we replace toroid cores with ee types , zobel network resistor becomes more warm..is it true ? can we reduce output HF with suitable filter ?

Regards
 
What is the differences between EE type cores (ER-ETD-EE,etc) and toroid cores in class-d application ? because i think when we replace toroid cores with ee types , zobel network resistor becomes more warm..is it true ? can we reduce output HF with suitable filter ?

Hi IR,

not all toroid cores , only iron powder core with low AL value is good for class d(b'cause they have enough air gap) or toroid ferite core with 1.2mm gap is suitable for 500W RMS class d amp.

Regards
MANOJ
 
what is the effect of gate resistor on mosfet dissipating power and fsw of amp ?
39 ohm gate resistor is good for 250~300KHz and IRFB4227 ?

Hi IR,

gate resistor is very critical on high frequency side. MOSFET gate capacitor increases the resistor value decreases and gate current will increases
practically i found that freq.=300Khz=130nC = @1A and i don't know the calculation

another i found above 25 ohms gate resistor will give the stability (max.100R)

Regards
MANOJ