TAS5805M: Device gets very hot

Hans van Daal

Part Number: TAS5805M

When playing audio the device temperature goes up to 127 degr.C, even without connecting speakers. PVDD = 24V. When PDN = low, the temperature is good.

2 months ago

0 Isaac Buliva 2 months ago

TI__Expert 3630 points

Hi Hans,

In your schematic, the ferrite beads being used for output filtering (L500/L501/L502/L503 - BLM18AG601SN1D) are rated for a current of 500mA, this could be the cause of the thermal issues depending on your speaker load impedance which will change your peak current. If the ferrite bead is overdriven, its actual impedance is reduced and the amplifier gets directly exposed to the capacitance of the filter.

Regards,

Isaac

0 Hans van Daal 2 months ago in reply to Isaac Buliva

Prodigy 70 points

Hi Isaac, do you have a suggestion for the ferrite beads I can use? We are using 8W/8ohm speakers.

0 Hans van Daal 2 months ago in reply to Isaac Buliva

Prodigy 70 points

Hi Isaac,

I have replaced the ferrites with part HI1812V10R-10 (8A), but still getting hot (up to 100 degr C).

Regards,

Hans

0 Isaac Buliva 2 months ago in reply to Hans van Daal

TI__Expert 3630 points

Hi Hans,

I would suggest checking the Thermal design considerations for TAS5805M, as well as the LC Filter Design Application Report. In general, ferrite beads cause a high-frequency current to pass through the load causing worse thermal performance, whereas an LC filter allows the switching current to flow in the filter instead of the load allowing for a better thermal performance. There are also PCB layout guidelines available in the datasheet which are optimized to improve thermal performance.

Regards,

Isaac

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TAS5805M: Device gets very hot