TDA7293/4 Compatibility

[Hakimi]

Hello, based on my finding for my amplifier, some of the thread in diyaudio state TDA7294 and TDA7293 are pin compatible.
However, from datasheet, TDA7293 has bootstrap loader and buffer driver pinwhich is pin 11 and 12, While TDA7294 pin 11 and 12 stated N.C( not connected)..

So , what the function of 'bootstrap loader' and 'buffer driver' pins ?? what happen if we leave the pin unconnected ??

If the pin are compatible, can i use PCB for TDA7294 to put TDA7293 there??
because here in malaysia, TDA7293 few bucks cheaper than TDA7394. (it may be a bit difference but i'm gonna make the amp about 4 channel, it cost me more!)

OR any one here has PCB for TDA7293 that tested working fine??


Thanks for helping for my first chip amp...

[pacificblue]

Pin 11 is only there for modular applications, i.e. when you use two or more amps in parallel. That pin is left disconnected for a single chipamp.

Using pin 12 for the bootstrap cap instead of pin 14 allows for increased supply voltage (120 V instead of 100 V). You can leave it disconnected, if your supply voltage is lower than 100 V and if you connect the bootstrap cap to pin 14 instead.

Yes, you can use the TDA7293 on a board that is designed for the TDA7294.