tda7265 2.1 channel home theater / car AMPLIFIER board

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• High Output Power -  30 + 30 + 60  watt RMS output power.*
• Low Distortion - Less then 1% Total Harmonic Distortion at 25 watt power output using 8 ohms speakers and 1K Hz sine wave.*
• Speaker usability - 4 & 8 ohms, 50 watt to 200 watt speakers can be used with this amplifier.*
• Single Supply Circuit -  12v, 24v or 36v battery operable,  ideal for using in Cars Tractors, Auto rickshaw Buses & Trucks. 
• Standard Components - All components used are available online or at your local electronics store.
• No SMD components - only through hole components are used makes soldering and replacement hassle free. 
• Cost Effective  -  This amplifier can be made in a fraction of cost compared to similar  high performance amplifier available in market.

                                           * as per TDA7265 STMicroelectronics datasheet.

                                                                Click Here  to download Blackbuck 2.1 channel TDA7265 circuit diagram 

The circuit has Three sections, stereo amplifier made using ic U2 and Bridge amplifier made using ic U1 and Low pass filter using U4.

Stereo Amplifier made of ic U2 -

Input signal is fed to pin no.7 & 11 (Non Inverting Input) through C1 & C2.

R1 & R4 connected to Pin no.8 (Inverting input) set the closed loop GAIN of left channel amplifier. 

Likewise R2 & R3 connected to Pin no.10 (Inverting input) set the closed loop GAIN of right channel amplifier. 

Changing the value of any one or both of these resistors will change the GAIN of the amplifier. 

Pin no.5 ( Mute ) is provided positive voltage to keep ic U2 active by voltage divider made of  D1, R5 & R6.

Pin no.3 is positive supply, Pin no.1 & 6 are ground. Pin no.2 & 4 is the output pins.

Please note that the Metal Tab of ic U2 is connected to ground pin no.6, so ic U2 can be fitted directly on heatsink. 

Bridge Amplifier made of ic U1 - 

Input signal is fed to pin no.11 (Non Inverting Input) through C11.

R12 & R14 connected to Pin no.8, likewise R11 & R13 connected to Pin no.10 (Inverting input) set the closed loop GAIN of the amplifier. 

Changing the value of any one or both of these resistors set will change the GAIN of the amplifier. 

Pin no.5 ( Mute ) is provided positive voltage to keep ic U1 active by voltage divider made of  D2, R15 & R16.

Pin no.3 is positive supply, Pin no.1 & 6 are ground. 

Pin no.2 & 4 are output pins connected to speaker.

Please note that the Metal Tab of ic U1 is connected to ground pin no.6, so ic U1 can be fitted directly on heatsink. 

Low Pass Filter

 ic U4 is used to make low pass filter.

Potentiometer RV1 is used to set the gain of low pass filter.

Capacitor C20, C21 and Resistor R21, R22 determine the frequency response of the low pass filter.

Changing the values of the above components will change the frequency response of the low pass filter.

Voltage Regulator ic U3 is used to provide fixed voltage to ic U4.

• U1 / U2 - TDA7265, TDA7269, TDA7292, TDA7499
• U3 - L7812 / L7815
• U4 -  NE5532, TL072, JRC4558, LM833, OPA2134 

                 *Supply voltages and output power vary, please read datasheet carefully before use.

• Type of PCB  - Single sided, Glass Epoxy FR-4 Grade A  
• PCB Size -  133 mm x 66 mm (  5.2 inch x 2.5 inch ), PCB Thickness = 1.6 mm,  
• Thickness of copper on PCB - 35 micrometer 

PCB designed with thick copper tracks & large solder pads to facilitate straightforward  placement and soldering of components.