TDA7386 Power Amplifier

I will give an explanation of TDA7386 Power Amplifier for previous post Making Surround Amplifier TDA7386 4 Channel.

TDA7386 Pins:

Pin 1 TAB: Connection to the metal plate of the integrated circuit, it is connected to negative.

Pin 2 Negative at power output (P2)

Pin 3 Amplifier output 2 (-)

Pin 4 Standby. Ignition at voltage greater than 3.5 volts. Off at less than 1.5 volts.

Pin 5 Amplifier output 2 (+)

Pin 6 Positive recommended 14.4 volts

Pin 7 Amplifier output 1 (-)

Pin 8 Negative at power output (P1)

Pin 9 Amplifier output 1 (+)

Pin 10 SVR Capacitor 47 uF 16V to earth.

Pin 11 Audio Input Amplifier 1

Pin 12 Amplifier audio input 2

Pin 13 S-Gnd grounded audio (negative, see considerations).

Pin 14 Audio Input Amplifier 4

Pin 15 Audio Input Amplifier 3

Pin 16 AC-Gnd capacitor 0.47uF to ground.

Pin 17 Amplifier output 3 (+)

Pin 18 Negative at power output (P3)

Pin 19 Amplifier output 3 (-)

Pin 20 Positive Recommended 14.4 Volts

Pin 21 Amplifier output 4 (+)

Pin 22 Mute, Mute to less than 1.5 volts, with sound after 3.5 volts.

Pin 23 Amplifier output 4 (-)

Pin 24 Negative at power output (P4)

Pin 25 Offline

Due to its high consumption, extreme care must be taken with the ground and power connections.

In addition to the ground connection of the pin 13 must be connected to the audio input section and

A common ground that is not direct to some negative of an exit.

Usually a common point is used to the power capacitor

Technical Details :

In the specifications we speak of 49 W for each channel.

We can say that it is not really as powerful as it can deliver around 20 watts per channel at low distortion levels with a load of 4 ohms and power of about 14 volts, plus the maximum total heat dissipation is 80 watts ( @ 70 ° C).

This audio amplifier is designed for car radios, used in Sony®, Kenwood®, Pioneer® and other high-end radios.

But each channel of the TDA7386 can develop 49 W at 15.2 volts with a load of 4 ohms with very high distortion and saturation levels.

Still it is of high power and by its few components is an amplifier easy to construct.

The power supply should exceed 15 amps and should not exceed 18 volts.

Schematic Diagram of the TDA7386 Power Amplifier based on the data sheet of the manufacturer:

In this amplifier the audio gain is fixed (26dB)

The pin 10 SVR capacitor should not be less than 10 microfarads and helps to reject noises

From the power supply.

All capacitors are 16 volts but may be higher voltage.

The manufacturer recommended capacitor value for each input is 0.1 microfarad (104).

 In automotive radios the heatsink is quite reduced so for a more continuous home working amplifier a good heatsink should be used and a fan can be added from those that use computer sources.

In order to avoid introducing noise we add a resistance of 33 ohms 1W,

In addition to a capacitor of 220 microfarads of 16 volts or greater.

It is worth repeating that the life of the electronic components decreases by working at high temperature.

In addition incorrectly connected lands (-) can cause annoying noises

Or even oscillations that may damage the integrated circuit.