how far can we drive LME49810,LME49811,LME49830

hi there can you tell me how this can be bridged? Im trying to achieve as much as 1200W in 8 ohms or preferably more than that...  The application for this for Public Address amplifiers where the requirement goes beyond 2000W rms into 8ohms there is one Labgruppen amplifiers can deliver more than 4000 in 8 ohms... ofcourse there are speakers to handle that kind of power. 

Can you please tell me how to bridge these? can you just post a generic schematic? how far will these be stable? Im telling you im struggling to get more power where 300 to 400rms is not sufficient. We are using all BJTs to IRF hexfets for the output stages... please help me...

we have sources for 7kva Unicore defense grade transformers for this application very powerful indeed. Infact I had a request for TI if they can make something of this level especially for mosfets.  If the current LME49830 be bridged then nothing like that. I would love and right from small amplifiers to multi kilowatt amplifiers we can go with one model to purchase and all in bulk.  We have standardized using IRFP240 9240 for basic amplifier to 350w into 8 ohm amplification. 

The next version please please try to release a new version of IC which can go instead of just +/-100v let it be +/-200v so that globally it can beat any amplifier in the world. How long it would take to release such product.  Everybody knows that class AB amplifiers are still the best in terms of quality power and sustained output but class D, H TH taking away the market as they are just rating high. 

we have one of our product designer who has 25 years of expertise in using wide spectrum of products a yet himself is from a family of guitar players and also an acoustic engineer and also does alot of live performances says that a 600w dynacord class AB amplifier beats the pants of Labgruppen amplifier rated at 6000watts of power the stroke of AB is different when I checked the schematics of the Dynacord amplifier it has supply voltage of +/-132 volts and being drive by 6 pairs of output transistors. 

I just have that one thing in mind when you have done all these upto +/-100v  voltage driver why cant you go upto +/-200v that makes us the market rock.

please put this proposal to the Technical team we are ready to pay Triple the price of the current driver chip.

Hi Sandeep,

To answer your question regarding bridging, yes topologically bridging is possible. It really isn't any different then any standard amplifier that has two outputs that are commonly switched on the back of the unit; ie inverting the input signal and sending to the second output.

I would treat each amplifier the same; ie either both inverting or both non-inverting mode and then create a single-to-differential converter at the input to drive the two different amplifiers. Any of these driver devices can be treated as a high voltage op amp from a topological standpoint.

I appreciate your feedback and desire for a +/-200V device; your input is noted.

Thanks and Best Regards,

JD

8306.LME49830_Brid.TSC

I have uploaded the TinaTi model can you please check it is that how we can bridge the LME49830?

I am talking about bridging of the voltage driver chips not the output stages. Are you talking about bridging the voltage drivers?

If anything is wrong can you correct that in the schematic please ? It will be very very helpful..

Hi Sandeep,

What are you trying to achieve by connecting the drivers this way? Previous posts above seem to indicate that you want very high power. 

I was talking about bridging two independent amplifiers (two drivers and two output stages).

Best Regards,

JD

im trying to achieve more power out of the amplifiers

can you tell me one thing how many pairs of IRFp240 and 9240 are required to be driven continuously at 2ohm? and at what voltage?

Hi Sandeep,

I'm not sure if you've seen this document or not, but it has some of the PD information you are looking for.

http://www.ti.com/litv/pdf/snaa058a

the number of FETs you use will depend in part on how conservative you want your design to be and how well your thermal design mitigates the heat; ie. the size, spacing and thermal resistance of your heatsink(s), whether a fan or other cooling is used, as well as how you define "continuous" and what the signal type is (audio or other).

Best Regards,

JD

Hello Sandeep,

You can use this formula to calculate maximum power dissipation at class AB for a sine wave:

For single ended:

P_dmax = |Vcc-Vee|²/[2*(pi²)*R_L]  [W] , per channel

For bridge applications:

P_dmax = 2*|Vcc-Vee|²/[(pi²)*R_L] [W], per channel

You should pay attention to maximum power dissipation of 150W per device at 25ºC, you should use the power devices at 50%-75% of it's maximum power, because increases long term reliability.

P_device = P_dmax / (number of output devices in one output channel) [W]

You should see if the V_DS and ID ratings are not exceeded, and if possible leave some margin.

Maximum absolute values for IRFP240/9240 pair at T_amb = 25ºC:

|V_DS| = 200 V  and |I_D| = 12 A 

I hope that this information helped,

Best regards,

Daniel Almeida

If I want to design a mosfet output stage with polar transistor in order to form a complementary feedback pair circuit.

Which is suitable component, LME49830 or LME49811 or LME49810. Thanks