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TL074: Max power and supply current of OP

Leo Chen
Prodigy 50 points
Part Number: TL074

Support Path: /Reference designs/Technical support help for a specific technical issue with a reference design/

TL074 max supply current for each Op is 2.5mA. In my operation, I measure total current from supply voltage. 10mA for +15v. 20mA for -15v. Base on this operation, I have the following questions: 1. Is max input supply current for TL074 2.5A * 4=10A ? Or based on Iik input clamp current spec 50mA? What’s the max power spec of TL074 2. If I calculate Tj of Tl074 not over spec 150 degree, should I still need to worry about the total power consumption and max input current spec?

  • 0
    TI__Guru*** 146826 points

    Leo,

    1) No, 10 amperes current won't happen. Input current and supply current are not the same thing. Maximum power should be limited to keep die temperature below 150C. However long term operation at 150C will shorten device lifetime. 

    2) Input current can be easily controlled in the application design and most designs only have picoamperes of input current.

    For your application where VCC+ current is 10mA and VCC- current is 20mA, that probably means the four output channels source about 4mA and sink 14mA. It is unlikely that any of the current is flowing on the input pins.

  • 0 in reply to Ron Michallick
    Prodigy 50 points
    Yes. Is there any spec about max supply current of TL074? Should I use iik 50mA as max supply current spec? Thanks for your reply.
  • 0 in reply to Leo Chen
    TI__Guru*** 146826 points

    Leo,

    There are two viewpoints for this. One is from the TL074 performance view; there is no supply current limit, as all four amplifier output are protected from shorts. The application must ensure junction temperature is not exceeded per AMR table in data sheet.

    The other is from an external power supply demand point of view. In this case, maximum current is 10mA plus maximum output current used by application.

  • 0 in reply to Ron Michallick
    Prodigy 50 points

    Hi Ron, 

    So, I just need to make sure Tj not over 150, and don't need to worry about the max supply current rating.

    In my operation, Can power  be easily calculated as 15v* 10mA + -15v* -20mA =  450mW  right? 

    Thanks 

  • 0 in reply to Leo Chen
    TI__Guru*** 146826 points
    Leo,

    Your formula is only correct if the outputs are 0V. The power can be somewhat lower or higher depending on output voltage(s) and output current(s). The value is a good starting point.