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.

TPA3118D2: Audio AMP questions

Part Number: TPA3118D2

Hi

Customers want to use TI / TPA3118D2DAPR to achieve 2.1-CH (left channel 15W speaker, right channel 15W speaker plus 30W bass)

1. Can our above TI / TPA3118D2DAPR design support 12V input and use 4-ohm speakers?

2. Following the question, what can or cannot be the reason?

  • Hi Gareth

        With 12V input and 4Ω speakers, you can realize 2 channel 15W output, but can't get 30W bass. Because the output voltage won't exceed input voltage, also around -0.5dB voltage may lost on MOSFET Rdson and inductor. So around 11.3V may finally reach to speaker, this is the highest voltage. When you calculate power, you need to use RMS value, that is 11.3^2 / 2 / 4 = 15.96W. This is the highest power you can get from 12V input, no matter you use BTL or PBTL mode.

  • Hi Shadow

    Power = Voltage Square / Impedance But the value in the calculation is divided by 2 May I ask why?

    Thank you

  • Hi Gareth

        As I said you need to use RMS value to calculate power, would the following formula be more familiar to you?