TDA7294 Mute/Stdby

Sangram

Moderator
Paid Member
2002-09-25 11:01 am
India
TDA 7294 mute and standby are voltage driven, not current. >3.5V on the relevant pin will turn the amplifier into active state.

The ST datasheet also has a recommendation for specific turn-on of the two pins (stby turn on before mute, switch off after). It is not recommended to stray for those recommendations.
 

Sangram

Moderator
Paid Member
2002-09-25 11:01 am
India
Hi

Can you post a hand-drawn schematic of what you have done?

A voltage pin will draw very little current so if the mute cap is too big you have to create mute condition by driving the pin low (short to ground) instead of opening the drive voltage.
 

Sangram

Moderator
Paid Member
2002-09-25 11:01 am
India
It depends on the capacitor value.

At 33V, a 10uF capacitor will have a pretty long hold-up time and will continue to feed the pin.

You can sort this out by adding a 2K resistor across the mute cap. This will act as a voltage divider in conjunction with the 10k Rmute. A 5.1V zener or three LEDs in series will also perform a similar function.