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TPA3116D2: TPA3116D2 Power Supply

Brian Lancelot
Prodigy 110 points
Part Number: TPA3116D2

Hi,

In the process of building a system with the TPA3116D2 in a 2.1 channel set up using 8 ohm speakers. The speakers are two 3" Full Range 8 ohm drivers rated at 30W RMS (83db sensitivity) and one 6.5" Woofer 8 ohm driver rated at 50W RMS (86.5db sensitivity).

What would be the power supply requirements to get the best out of the amp and speakers. Am planning on a 24V power supply. What should be the amperage of the power supply to get the lowest THD and highest output?

Your help will be appreciated. 

Regards,

Brian

  • 0
    TI__Expert 6985 points

    Hello Brian! I assume you are using the master/slave configuration of 8.2 Typical Application with the woofer in PBTL? What frequency and modulation scheme are you intending to use, and what is the actual maximum power that you expect to drive the speakers, the rated maximums you noted? 24 volts should be fine for performance as long as you can drive more than 6A. Please note that the 7.5A is the Over current trip point.

    Shawn, Do you have any other recommendations?

    Thanks, Jeff

  • 0 in reply to Jeff Kohnle
    Prodigy 110 points
    Thanks Jeff for your prompt reply.

    My 2.1 boombox (FAST setup) would be using one TPA3116D2 for driving the two 8 ohm Full-Range Satellites 30W X 2 = 60W RMS and the other to drive one 8 ohm Woofer 50W x 1 = 50W RMS. The FR's are each rated at 30W RMS and 60W Max and the Woofer is rated at 50W RMS and 100W Max.

    I guess the power requirements would be around 120-140W to get 110W RMS from the system. So, 24V 5A or 24V 6A should be handy. I think I would go with your recommendation of 24V 6A so that there is enough current to drive the 8 ohm speakers. I hope to get < 0.1% THD levels with this power supply.

    Hope, I am on the right track with this.

    Regards,
    Brian
  • 0 in reply to Brian Lancelot
    TI__Expert 6985 points
    These power levels into 8 Ohms should be OK for THD.

    Hello Shawn! Do you have any other recommendations or thoughts? Thanks, Jeff
  • 0 in reply to Brian Lancelot
    TI__Mastermind 24835 points
    Hi Brain,
    I fully agree with Jeff's calculation.
    According to your description, there isn't any problem in 2*30W BTL mode with 8ohm/24V application. But there is some problem in 50W output with 8ohm/24V. You need to use a lower resistance speaker for these high output power application. Because output swing is around but less than 24V when PVCC=24V. Please refer to figure 13, the output power is less than 35W without clipping. I think you could try 4ohm or 2ohm resistance speaker for 50W output.
    BTW, for these high output power application, please pay highly attention to the thermal performance during PCB layout design. Please refer to section 10 Layout in TPA3116D2 datasheet.
    Best regards,
    Shawn Zheng
  • 0 in reply to Shawn Zheng
    Prodigy 110 points

    Thanks Jeff.

    Shawn,

    Are you saying that the TPA3116D2 will struggle to output 50W RMS x 1 to a single 8 ohm Woofer. As I have mentioned, the plan is to use TWO TPA3116D2 amps in a 2.1 configuration with one driving two FR speakers (30W x 2) in STEREO mode and the other driving a single Woofer (50W x 1) in MONO.

    When you mention Fig 13., I can see that with 24V supply we get 35W output without clipping. Is this with a Single TPA3116D2 and is it 35W per channel? Are all those graphs per channel or total output?


    Regards,
    Brian

  • 0 in reply to Brian Lancelot
    TI__Mastermind 24835 points
    Hi Brian,
    Yes, I understand that one TPA3116D2 is used in BTL mode to output 2*30W power, and the other is used in PBTL mode to output 1*50W power. Let's say the output sinewave swing is +/-24V, the calculated output power is 36W(24*24/8/2) on 8ohm load.
    For the chart, it's for one channel, but the output power limit is the similar for BTL and PBTL. PBTL mode is to support lower resistance speaker then higher output power and avoid OC FAULT - because the output current is divided into two channels. So you need to use a lower resistance for 50W output power.
    Best regards,
    Shawn Zheng
  • 0 in reply to Shawn Zheng
    Prodigy 110 points
    Thanks Shawn.

    I will take your advice and go with 4 ohm Woofer for the mono / PBTL setup. The Woofer I had shortlisted is also available in 4 ohm and outputs 60W RMS (120W Max) with 88.3db sensitivity.

    So, now I will go with two 8 ohm FR 30W RMS x 2 and a single 4 ohm Woofer 60W RMS x 1 for my 2.1 set up.

    Do I use the same power supply 24V 6A for this set up or do you have any other recommendations.

    In fact, could you suggest the power supply options for the below 2.1 set ups:
    1) Two 8 ohm FR 30W RMS x 2 and a single 4 ohm Woofer 60W RMS x 1
    2) Two 4 ohm FR 30W RMS x 2 and a single 4 ohm Woofer 60W RMS x 1

    Thank you once again for your prompt replies.

    Regards,
    Brian
  • 0 in reply to Brian Lancelot
    TI__Mastermind 24835 points
    Hi Brian,
    I think 6A current on the power supply is a little lower, considering that the output power is 120W now. If you could use 24V 6.5A or 7A power supply, it would be good.
    Best regards,
    Shawn Zheng
  • 0 in reply to Shawn Zheng
    Prodigy 110 points

    Thanks Shawn.  Will go with your recommendations of 24V 6.5 or 7A.

  • 0 in reply to Brian Lancelot
    Prodigy 110 points
    Hi Shawn,

    I have shortlisted the Meanwell 24V 6.5A.

    Just one point of clarification. The total output from the power supply will be 150W-156W. So, total power requirement is not an issue. Buy, what about the Amperage? Is that sufficient for the 2.1 setup or will the 4 ohm Woofer require higher Amperage to drive it and it will try to pull more current from the power supply.

    Regards,
    Brian
  • 0 in reply to Brian Lancelot
    TI__Mastermind 24835 points

    Hi Brian,

    For 4Ohm woofer, the maximum output power is 60W. Form Figure 16 in TPA31162 datasheet, the efficiency is around 88% with 24V power supply and 4Ohm load. Then the power from the power supply is 68.2W, and the current on the power supply is around is 2.9A. You can calculate the power supply current for the tweeter by the Figure15 in the datasheet. I think it should be OK, but you could use higher current ability power supply to reserve more margin.

    Best regards,

    Shawn Zheng    

  • 0 in reply to Shawn Zheng
    TI__Mastermind 24835 points
    Hi Brian,
    Please feel free to let me know if you have more question on this. Could you please close this question if it's answered?
    Best regards,
    Shawn Zheng