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DAC81404: How to get a information for 'High Current Drive (1 A) Application' in DAC81404/DAC61404 datasheet?

Lee SungYun
Intellectual 295 points
Part Number: DAC81404

Hello?

As title, I want to know for high current driving application.(using limit 200 mA Max.)

But I can't find a information of parts(R, C, TR, etc.) in application.

Please reply.

  • 0
    TI__Guru 53183 points

    Hi Lee SungYun,

    Akhilesh will help with this when he is back in office after the local holidays.

    Thanks,

    Paul

  • 0 in reply to Paul_Frost
    Intellectual 295 points

    Thank you for reply.

    I'll waiting for that person to come back.

    Is that person coming next year?

  • 0 in reply to Lee SungYun
    TI__Guru 53183 points

    Yes, the will respond on January 2nd.

  • 0
    TI__Mastermind 18816 points

    Hi,

    Please have a look at the DAC81404EVM user's guide schematics. EVM schematics has all the values and designed for 100mA load capability.

    https://www.ti.com/lit/pdf/slau825

    After going through the same, if you need more help, please post it here.

    Regards,

    AK

  • 0 in reply to Akhilesh K
    Intellectual 295 points

    Hello?

    I've reviewed DAC81404EVM, but it is slightly different from the application on the datasheet.

    In datasheet, it is completed with a pair of transistor and a combination of resistor + capacitor.
    On the other hand, the circuit you told me requires a fairly large area as 4 resistors and 2 diodes are added to 3 transistors.

    Accordingly, we ask for the resistance value and the product name of the transistor used in the 1 A application on the datasheet.(Ccomp is assumed to be 470 pF)

    In addition, in the case of the EVM circuit, if the load is increased to 200 mA, I would like to ask if there is any element limiting the current or if only the resistance of 5 Ω and the heat dissipation of the transistor can be considered.

    Thank you.

  • +1 in reply to Lee SungYun
    TI__Mastermind 18816 points

    Hi,

    Current limit is achieved by resistor 4.99ohms and transistor Q2 in the EVM. When the load current is above 120mA, drop across resistor will be above 0.6V which will turn on the transistor Q2 and limits the current.

    Datasheet shows basic circuit, but if you want to go for actual implementation, I suggest go with the EVM circuit. for 1A application you may need to change the resistor and transistor.

    NPN = MJE3055

    PNP = MJE2955

    For current limiting 1A, I suggest R30 and R31 replace with 0.6 Ohms. Also please note, current limiting is implemented only for sourcing. If you want the same for sinking, please add another PNP transistor

    Regards,

    AK

  • 0 in reply to Akhilesh K
    Intellectual 295 points

    I'll review 2 applications.

    Thank you for reply.