hi forum.
I'm working on this Chinese Soundigital replica. The main difference is the output drivers. Instead of using a zxgd3005 like the original SD or other chinese replicas use, it uses 4 buffer transistors. This changes the way the gate of the power transistors is handled. I have used the usual references used in original SD and Chinese replicas, but without successful results. The amplifier turns on, but with a minimum load of 100w it goes into protection. The power transistors of this amplifier are marked as P2 and the packaging is INFINEON OPTIMOS 3 or OPTIMOS 5. It has a gate resistance of 33ohm originally. 170khz oscillation and 140v. Has anyone worked on these chinese SD plates and knows the original P2 reference? Or how can I calculate the gate resistance to modify the gate resistance so that the power mosfets work properly?
I'm working on this Chinese Soundigital replica. The main difference is the output drivers. Instead of using a zxgd3005 like the original SD or other chinese replicas use, it uses 4 buffer transistors. This changes the way the gate of the power transistors is handled. I have used the usual references used in original SD and Chinese replicas, but without successful results. The amplifier turns on, but with a minimum load of 100w it goes into protection. The power transistors of this amplifier are marked as P2 and the packaging is INFINEON OPTIMOS 3 or OPTIMOS 5. It has a gate resistance of 33ohm originally. 170khz oscillation and 140v. Has anyone worked on these chinese SD plates and knows the original P2 reference? Or how can I calculate the gate resistance to modify the gate resistance so that the power mosfets work properly?
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Is it using the over-current protection in the 20957?
Do you think that's what's shutting the amp down at 100w?
Do you think that's what's shutting the amp down at 100w?
If they're using the on-board over-current protection and you're using a replacement output FET with higher RDSon than the original, the IC will shut down prematurely.
I have used several references with different RDSon values, but with the same results. Is there any way to adjust the circuit?
The circuit can be reprogrammed but if you use an output with higher RDSon, they may fail.
Do you see programming resistors on the OC terminals of the 20957? If so, you can adjust those to make it shut down later.
Or, does this amp use the 5-pin IR25750 for protection?
Does this amp have an LED indication that the amp is shutting down due to an over-current fault?
Do you see programming resistors on the OC terminals of the 20957? If so, you can adjust those to make it shut down later.
Or, does this amp use the 5-pin IR25750 for protection?
Does this amp have an LED indication that the amp is shutting down due to an over-current fault?