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Headphone Amplifier ( L78MXX V. Reg. - TDA 1308 - TL071) Help Please

Ismail Ozmen
Prodigy 30 points
Other Parts Discussed in Thread: TL071, TL972, TPA6111A2

Hi, I need help with this circuit about voltage regulator, TL071 and TDA1308.
Could you please give me some information?

It may be easy for you but I am having difficulty and it is very important for me.

The circuit must be suitable to work with an input source of high impedance such as guitar pickup and an output load of low impedance such as headphones.
Need to justify the choice of the TDA1308 amplifier, the TLO71 operational amplifiers and the voltage regulator.
I have to state a suitable voltage regulator output voltage.
Justification for the choice of integrated circuit must specifically make reference to the technical characteristics of each integrated circuit.

I have tried to build the circuit with TINA and I couldn't find 78M voltage regulator.

No source source is connected to the TL071 amp. Do we not have to connect a source? 

Thank you.

  • 0
    TI__Guru**** 151776 points
    Ismail,

    I suggest LP2985-50 for regulator, TL972 for pre-amplifier, and TPA6111A2 for headphone driver.
    Adding some voltage gain is recommended. I see a gain of only 1.
    What is your VIN voltage? I might have to change the Vreg.
  • 0 in reply to Ron Michallick
    Prodigy 30 points
    I cant find the LP2985-50 regulator. However, I cant change the components. I have to prepare assignment about this circuit. Need to find out voltage requirement, output voltage of the regulator, why TDA1308 and TL071 are used.
  • 0 in reply to Ismail Ozmen
    TI__Guru**** 151776 points
    Ismail,

    Thank you for the clarification about your task.
    L78MXX is not a part number. the XX needs to replaced with 05 because the TSA1308 needs 5V.
    The uA78M05 and LM78M05 is the TI pin 2 pin replacement.

    TL071 minimum recommended supply voltage is +/-5V or 10V signal supply.
    It won't work well at 5V. The common mode input and output range are not rail to rail.
  • 0 in reply to Ron Michallick
    Prodigy 30 points

    Thanks for your reply and help. I appretiated. Unfortunately, I dont have UA78M05, LM78M05 and TDA1308 in my library. I dont know what to do.
    I can't design this circuit :(
    I dont want to fail. I have to justify TDA1308, TL071 and voltage regulator.
    Where I have to connect the supply voltage for TL071?

  • 0 in reply to Ismail Ozmen
    TI__Mastermind 24885 points
    Ismail,

    Unfortunately we cannot complete your assignment for you.
    Your best bet is the datasheet for each of these ICs. This provides information about each of the pinouts of the devices, including the pinouts for every available package.
    Supply, input, output voltages, etc. can found in the specifications section for each of these devices so that you know what supply voltages are appropriate for a given device.

    Regards,
    Michael