Hi all,

I am using the test circuit that is provided by the TDA 2003 data sheet to make an audio amplifier. but the output i am getting looks like a half wave rectifier output. i cann't understand why. any help much appreciated.

 

Hello,

Can you post a schematic?
It looks like a dc offset somewhere.
What is your powersupply?

Greetings,
Bertus

 

here is the data sheet for TDA.

http://www.st.com/stonline/products/literature/ds/1449.pdf

 

Did you bias the amplifier to output a voltage of half the supply voltage when no signal is present?

 

Hello,

Are the capacitors in the right order ?

Take a look at C2 direction.

Greetings,
Bertus

 

i didn't bias the amplifier. i read it has its own internal biasing.

i have (+) of C2 to pin 2 and (-) to R1 and R2 junction.

 

Hello,

So C2 is correct mounted.
What is the voltage you are using ?
It should be between 8 and 18 Volts.

Greetings,
Bertus

 

i didn't bias the amplifier. i read it has its own internal biasing.

i have (+) of C2 to pin 2 and (-) to R1 and R2 junction.

At which page did you read that?

 

i found what was going on with that. i was not using proper attenuation.now the circuit is working properly so far. thanks for all your help.

 

Hello,

Glad you found the trouble.
Only 50 mV is needed to have full output.

Greetings,
Bertus

 

Did you bias the amplifier to output a voltage of half the supply voltage when no signal is present?

The test circuit in the datasheet does not show external basing resistors because they are built-in as shown on the schematic of the IC.