TAS5727 Over-Current Limit

Alex Fink

Other Parts Discussed in Thread: TAS5727

Hi,

Using the TAS5727 in a product, we are seeing current limit occurring at about 3A, whereas the amplifier spec says over-current limit protection is 4.5A nominal. Do you have any insight about this discrepancy?

Thanks.

Our power supply voltage is 19V. Our load impedance is 5.3 ohms.

I am attaching a trace of what happens below. The yellow and purple traces are the amplifier outputs, before the output filters. The green trace is the A_SEL/FLT pin, which goes low when the over-current event occurs.

over 7 years ago

0 Diego Melendez over 7 years ago

TI__Guru 57800 points

HI, Alex,

This behavior seems related to a false over current protection event. You need to set up Modulation Limit Register (0x10) to the minimum (0x07) when operating with PVDD voltager larger than 18V. This must be done to ensure enough time is given to get the bootstrap capacitor fully charged, because these caps are charged during the minimum PWM cycle. If the caps are not fully charged, then the power stage won't be fully turned ON, causing a false over current event.

Best Regards,

-Diego Meléndez López
Audio Applications Engineer

0 Alex Fink over 7 years ago in reply to Diego Melendez

Prodigy 70 points

This appears to have fixed our problem. Thank you very much.

Audio

Audio forum

TAS5727 Over-Current Limit