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.
Replies: 4
Views: 1193
Hello,
I have a application and need a amplifier :)
These are the specifications:
Frequency-range: 5Hz - 10kHzP_out: 5Wmax Voltage: 2.5V max. Current: 2,5A
The impedance of the load is between 0.4Ohm and 1.8Ohm within the specified frequency range. The max. Voltage will not occur with the lowest impedance, so that the specified max. current will not be exceeded.
Is it possible to use the TPA3116D2-Q1 for this load?
I mean is the limit for the min. impedance limited by the max. current? If this is the case, I would limit the max input to 0.3V with 20dB gain to limit the output.
In the data sheet it is specified to power 100W with 2Ohm what would mean a current of 7A [=SQRT(P_out/R_load)] which is far over the current that I need. Or am I wrong in my way looking at this? So I would think the TPA3116 could handle this low impedance if the output is limited by the input.
Or do you have a better recommendation for this application.
If I forgot any information please ask, I'm new in this field of application :)
Kind regards Tom
Hi, Tom
What is value of your PVCC? TPA3116 support 4.5V~26V operating voltage. If the Load's DC resistance is 0.4ohm, Pout=4.5^2/(0.4*2)=25.3w.
In reply to Peter Cao:
Hello Peter,
The PVCC will be 12V.
Pout = 12V^2 / (2*0.4Ω) = 180Watt
In the data sheet the max. output for mono is 100W, so 12V would be too much for my application if I would like to use the full range.
Do I see this right that this for the output of a 12V peak sine signal or let me say for the max. input signal?
Am I right if I say that the max. PVCC would be: sqrt( 100W * (2*0.4Ω) ) = 8.9V if i want to use the full range?
But what if I want a sine signal as output with voltages only between 0.5V and 2V (depending on the frequency (5Hz to 10kHz)).
For example if i take the max. 2V with the 0.4Ω my Pout would be only 5W. So could I use PVCC 12V if I control the output via the input signal in that way that I will only get this low voltage as output (with a 20db gain this would mean a max input of 200mV)? Or am I wrong in thinking that way?
In reply to Tom Viehrig:
What is the minimum load Class D can support? There are several reasons:
For example, TPA3118D2 is a pad down version and TPA3116D2 is a pad up version (with heat sink), since the over current trip point is the same, but the output power are different.
For example, PVCC=12V case. 8ohm load: efficiency=95% with @Pout=20w; 4ohm load: efficiency=90% with @Pout=20w;
For TPA3116D2 (with the Heat sink which you can find in EVM user guide), with PBTL, the device's power consumption (acceptable) is 10W without OT. You can find in below curve.