Categories: Power Amplifier

25/50 W Power Amplifier Class D based MAX9709 chip

Despite the relatively small power output specified in the title of the article, it has one distinct advantage – the acoustics can be connected directly to pins – no extra coils is not required – as they say – all included.

Features chips as follows :

Supply voltage,	:10 … 22V
Supply current absence of a signal, mA	:20mA
Maximum Power Output:
in stereo (CG = 10%)	:29W
in mono (CG = 10%)	:50W
“Normal” Power Output:
in stereo (CG = 0.1%)	:12W
in mono (CG = 0.09%)	:22W
S / N ratio (weighted)	:96%
Efficiency (max)	:87%

The device has built-in overload protection, output current limiting, suppression of the “click-and-pop” when you turn on and off. There is also a programmable gain amplifier and switch-off temperature.

As can be seen, the device is connected to two power supplies – 22 V – for analog and digital 5-12V. If it is assumed that the chip will be powered by 12 volts, the findings for the power supply can be combined. Otherwise, it is enough to feed the analog part to connect any integral stabilizer – TIPPING or LM.

Amplifier Circuit