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TPA3118D2: TPA3118D2 vs TPA3116D2

Brian Lancelot
Prodigy 110 points

Part Number: TPA3118D2
Other Parts Discussed in Thread: TPA3116D2, LM3886

Hi,

What are the total outputs at <0.1% THD+N levels for the TPA3118D2 at 4 ohms and 8 ohms with a 24V power supply?

From the graphs of the TPA3116D2, it seems the total output is roughly 35W at <0.1% THD with an 8 ohm load and around 65W at <0.1% THD with an 4 ohm load. But, what about the TPA3118D2?

Regards,

Brian

  • 0
    TI__Mastermind 24835 points

    Hi Brian,

    TPA3116D2 and TPA3118D2 share the same datasheet, the only difference is the package(thermal pad-up and pad-down). The measrement data for the output power in the datasheet is for transient output power instead of continuous output. Because output power ability depends on the system level thermal design very much. The performance is almost the same for the lower output power between 3116 and 3118. While for higher output, TPA3116D2 can output higher power without triggering thermal FAULT because it can work with a heatsink which helps a lot to dissipates the heat. For TPA3118D2, there should be no problem in outputing continuous 2*30W power on 8Ohm load as soon as the thermal design is good enough. But for 4ohm load, it can only output less than 2*20W output power because the efficiency is lower with lower load. And please be noted that, thernal performance is a system level issue, so the output power ability depends a lot on the thermal design.

    Best regards,

    Shawn Zheng   

  • 0 in reply to Shawn Zheng
    Prodigy 110 points

    Hi Shawn,

    You mention that the TPA3118D2 can output continuous 2*30W with an 8 ohm load. What will be the THD+N levels at this output. As per the graph for the TPA3116D2/TPA3118D2, the output with 24V and 8 ohm is around 2*30W with 0.5% THD+N at 1KHz. Now is this continuous or transient? Because, your first statement mentions that the measurement data shows transient output and not continuous output.

    Also, as a side question, I wanted to understand how the LM3886 chip fares compared to the TPA3116D2 with regard to total output and quality of sound. There are conflicting reports as to the sound quality of class A/B vs class D amps on the internet. Would value your opinion.

    Regards,

    Brian

  • 0 in reply to Brian Lancelot
    TI__Mastermind 24835 points

    Hi Brian,

    There isn't difference in THD performance between continuous output and transient output actually.So for THD performance, you can use the data in Figure 10 in datasheet. The cotinuous maximun output power depends on the thermal performance, while the transient maximum output power depends on OC THR.

    LM3886 is a very old device, and we can only provide very limited support on it due to the limited resource. The THD performance of both TPA3118D2 and LM3886 are in about the same level, but the later one has lower effieiency.

    Best regards,

    Shawn Zheng