LM 3886 bridged

[costy_ro]

Does someone have a pcb(or at least a schematic) for 2LM 3886 bridged?Something simple not too complicated
10X

 

[tiltedhalo]

LM3886 bridged??

What are you looking for exactly? Are you looking to invert at the chip or use a buffer like a DRV134 for the bridge, what voltage supply ect... theres alot of circuits out there, whats the load your going to be driveing ect......

 

[-_nando-_]

NEVER drive loads bellow 8 Ohms with 3886 bridged !

 

[tiltedhalo]

8 ohms

Ive driven loads as low as 3ohms bridged without an issue, just take a lot of thermal and current control work.

 

[costy_ro]

First,10x for the replyes.I want to invert the signal at one chip(as in the app notes),the load will be 5,7ohm,the supply voltage is not an issue(i`ll have one ordered as i need,i think +/-30V would be good enough-correct me if i`m wrong).

 

[costy_ro]

Nobody,not even a schemattic?

 

[Netlist]

costy_ro
http://www.national.com/appinfo/audio/files/BPA-200_Application_Note.pdf and this
is the thread you couldn’t find.

/Hugo

 

[heater]

OK How abot this one:

http://david.lewander.com/projects/amp/amp.htm

100 watss into 8 or 4 ohms depending on power supply voltages.

 

[Bazukaz]

I think it should deliver 140 W RMS into 8 ohms with proper supply voltages and large heatsink. I usually use a large aluminium sheet , at least 5 mm thick, it works well.

 

[costy_ro]

I was hoping to get about 120W into 8ohms with +/-30V.
Is it realy that necessary to have a 8ohm load?I`ll probably have a 6 ohm load

 

[costy_ro]

nobody made this amp yet?

 

[veteran]

Why not use a parallel configuration of two LM3886 or one LM4780 amp? No phase inversion needed and it can easily drive less then 8R speakers.

LM4780 stereo/parallel

 

[costy_ro]

i need min 100W(max 200W) into 6-7ohm load(real values)

 

[veteran]

Theoretically You should get 'real' 100W on 6R using this configuration of chip-amp. But if You wont more power - look for some discreet bipolar or mosfet amplifier.

 

[XELB]

NEVER drive loads bellow 8 Ohms with 3886 bridged !

I am driving 6 Ohms speakers with LM3886 bridged and they don't get very hot
My trafo is 20-0-20 .....


BTW, the LM3886 plays very well when it's hot

 

[costy_ro]

Theoretically You should get 'real' 100W on 6R using this configuration of chip-amp. But if You wont more power - look for some discreet bipolar or mosfet amplifier.

using +/-30V results 160Winto8Ohm load(using theOverture_Design_Guide13)
so i was hoping at least 120W

 

[Bazukaz]

Bridged amp will drive a load of 4 ohms , but the protection will not allow to reach the highest power levels.
To get 160 w RMS you will have to keep ur chip temperatores low.That means a large heatsink , and a fan. I think it is better to use 4 chips instead , and have 200 w RMS without a fan.
Did you read BPA - 200 app note ?

 

[costy_ro]

i want to use just 2 chips,and i don`t intend to use 160W;100,at most 120W;although the speakers i`ll use are rated at 200W RMS

 

[veteran]

So You don't have a choice Use both of them in parallel configuration.

 

[costy_ro]

i only have 4 chips for a stereo amp,in paralel,they don`t give 100W/8ohm;i`ll stick with the bridge config;with a power supply of +/-30V