Tda7294 dc volt

[prabanjas]

hI,

I am building a TDA7294 AMP. Help me on DC volt limit. I have a 35 0 35 rail and after regulated it gives +47 0 -47 v. May I use it for 7294??



Thx

[martinbls]

Hi!

In practise, I would not go to the maximum limits of a TDA7294. For a stable operation, I would recommend a transformer with 22-0-22 V rails for both 8 ohm and 4 ohm loads, and perhaps 25-0-25 V (up to a mximum of 30-0-30 V) for 8 ohm speakers only.

But that's quite allright. I build amps using TDA7294 and TDA7293 and these chips do perform very well with a 22-0-22 V transformer (around +-30V after rectification and smoothing caps).


Regards - martin

[sangram]

No.

The TDA7294 cannot operate safely with such high rails, it is specified for maximum operating voltage of 40V in high-efficiency mode or 35V in Class AB (normal) mode.

Since you have a regulated supply, I would advise you reconfigure the regulators to 35V rails. This should be relatively simple.

[Minion]

Ive got a TDA7293 running off of +/-42v DC and it runs fine but I believe it is the upper limit that the chip should be run at , I"m running my next Stereo TDA7294 off of +/-34v DC .....


CHeers

[kroto]

I want to build TDA7293, how to use the Clip detector with LED? just simply add a resistor and LED?

for mute and standby function, should it be powered from external supply(low voltage) or connect it from the +Ve main power?

[prabanjas]

For safe operation I changed the rail as per the advice and it works fine now with 25 0 25 rail. Sounds good.


If anybody have a nice mosfet or transistor circuit which is very stable with 35 0 35 rail (DC RANGE OF 50 V).. I want to build a subwoofer amp..


thx..

[PhilippeS]

My TDA7293 have +/-35V rails without any problem and the St.By/Mute is connected to +35V.

If you dont want a plastic box TV sound (Schematic in data is made for that use) :
replace the 22uF between 680 Ohm and ground by a jump and increase the 22uF bootstrap cap to a good 220uFcap (Elna Silmic)

Philippe

[Hannes1962]

Originally Posted by prabanjas

hI,

I am building a TDA7294 AMP. Help me on DC volt limit. I have a 35 0 35 rail and after regulated it gives +47 0 -47 v. May I use it for 7294??



Thx

Hi,there somwhere!
I have over 7 years built amps with these chips and my suggestion is to use power supply with not over 34 volts per rail.For bridge application i used phase-turner with opamps and the power i got was higher than with manufacturers suggestion (see the datasheet,it`s not good solution).With +/-
34 volts power supply (+15000 mkf ellytes per rail) i `ve got starting limiting sinus at 32 volts rms on 8 ohms.Remember that 0,1-0,5 mkf capasitors on power supply are needed as near as possible to chip to avoid self-oscillating and for low thd.Heatsink i use is allways with bigger surface area than suggested and allways with automaticaly powered ventilator.Never burned
any chip.And allways satisfied with sound.
Regards,
Hannes from Estonia..

[guaxian]

HOW ABOUT AC 30V?
+-42V is dangerous for TDA7294?

[Minion]

dh