This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPA3220: Lowest possible impedance

Part Number: TPA3220


As a hobby project I am designing automotive audio amp based on TPA3220 D-class amp. What is often happening with this automobile audio stuff is that speakers have quite low impedance (2 ohms or even 1 ohm). I have no concerns regarding 2 Ohm load - no doubt TPA3220 can drive that in PBTL mode. But what about load with 1 Ohm impedance? Product selector tells me that TPA3220 is capable of driving 1 Ohm load

But datasheet (which I trust more) tells that 1.6 Ohm is minimal resistance in PBTL load

On the other hand I understand that mentioned value (1.6) works when PVDD is 30 Volts. So DC current limit shall be 30/1.6 = 18.75 A. For my application PVDD will be at most 15 volts, so that current limit is unlikely to be reached even on 1-Ohm load.

Is there any other limiting factor restricting TPA3220 operation with such low-impedance load? And if no, what should I expect in terms of THD and power dissipation?

  • Hello Vadym,

    The main concern with low impedance load is triggering an overcurrent fault, if your operating conditions are managed such that you don't input a signal big enough to trigger an OC fault then that the device should be fine to operate as this is the main concern from a device operation/stability perspective. 

    I would recommend you validate your operating conditions on an EVM or system to ensure you are not triggering any fault conditions.

    best regards,