Hi,
I use TAS5630 in my design of D power amp (300W) with a transformer load in PBTL mode. I followed all recommendations of PCB, sloa133.pdf, heat sink have a good connection to PCB ground. But I found a problem, TAS5630 damaged after different times of work (sometimes 5-10 sec. sometimes 1-2 min). I know about different protect systems in TAS5630. That’s why I tried to know the situation and changed the load (resistance load) so that I had the power 300W. In that schema I found out the strange effect, PWM frame rate in OUT_X (400kHz I have in my design) changed according figure.
It’s like a change of PWM frame or a miss of a pulse that must be at list 250ns according page 10 tas5630.pdf. I changed the resistance load (4-Ω, 3-Ω, 2-Ω) and I found out that the missing of pulses took place when the amp power was about 220-240W in any load (4-Ω, 3-Ω, 2-Ω or else) and when the input sine went over its max and min. At the same time I had clip signal when the amp power was about 150W but according tas 5630.pdf that situation didn’t happen till RL = 2 Ω, 1% THD+N, unclipped output signal -480W page 10. According some recommendations of DC-DC converters I divided power GND and signal GND in my PCB design but without any result. I cant explain such a behaviour and ask your help.
Thanks and regards
Sergey Chernov.
