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# TPA3118D2: Can TPA3118D2 support 2x15W (stereo) and 1x 30W (woofer) @4ohm, 12V?

Part Number: TPA3118D2

In the datasheet, it said TPD3118D2 can support 2x 30W@8ohm, 24V. How about 2x15W (stereo) and 1x 30W (woofer) @4ohm, 12V?

Thanks

• Hi Jacky

You can realize 2x15W (stereo), but can't get 1x 30W (woofer). The PVDD voltage is too low, the max output voltage won't exceed PVDD voltage.

What is the max power can be support for woofer in TPA3118D2 PBTL with 4ohm, 12V? I asmue the efficiency is 85%, so (12x0.85)x(12x0.85)/4=26W, right?

• Hi Jacky

It's not so related to efficiency because we can increase the current when efficiency is low.

The Rdson of MOSFET and inductor will divide voltage from load. We usually assume a -0.5dB voltage will lost on these devices. So with 12V PVDD, the max voltage on load is around 11.3V. The output on load is always sine wave, you need to use the RMS value to calculate power. It's 11.3^2 / 2 / 4 =  15.96W.

• For stereo 4ohm, 12V --> the max output power is 15.96W and the current would be 1.14A at each channel, can the TPA3118D2 sustain the heat at 60C ambient temperature? if not, what is the max power can be supported for stereo 4ohm, 12V at 60C?

• Hi Jacky

We think there should be no problem to produce 15.96W. You can use more vias and copper on the PCB to help dissipate heat, and the heat sink can be considered.