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ULN2004A　hFE value

masahiko shimizu
Guru 11235 points
Other Parts Discussed in Thread: ULN2004A

Hi 

  My customer is using ULN2004A.

  Could you let me know hFE value of FET in ULN2004A at "0C, 20C and 40C" ?

Best regards,

Shimizu

  • 0
    TI__Guru* 97046 points
    Shimizu,
    Thank you for your post. The appropriate applications engineer has been notified and will respond shortly.
  • 0 in reply to Emrys Maier
    Guru 11235 points

    Hi Emrys,

     Thank you for your support.

     I wait your response.  

    Thanks 

    Shimizu

  • 0 in reply to masahiko shimizu
    TI__Mastermind 24985 points

    Hello Shimizu,

    Based on the datasheet in Table 6.6 the beta values are as follows at 25C:

    For II -250uA beta is approximately 400

    For II -350uA beta is approximately 571

    For II -500uA beta is approximately 700

    The beta values are going to increase with temperature.

    Is there a particular input current that you intend to run the device at or output current that you hope to achieve? Based on this I may also be able to provide an estimated range of beta values from 0C to 40C.

    Best,
    Michael

  • 0 in reply to Michael J Schultis
    Guru 11235 points
    Hi Michael

    Thank you for response.

    I request hFE value at the following condition.

    - 0C, 25C, 40C
    - 50uA, 250uA, 350uA, 500uA ,700uA

    Thanks
    Shimizu
  • 0 in reply to masahiko shimizu
    TI__Mastermind 24985 points
    Hello Shimizu,

    I am looking into this further, and I should have a response for you tomorrow.

    Best,
    Michael
  • 0 in reply to Michael J Schultis
    TI__Mastermind 24985 points

    Hello Shimizu,

    We do not have further data covering the ranges in question. The variation in Beta values is very large between devices so it is difficult to give a typical value.

    I do however want to correct one point that I made previously:

    The values quoted below are going to be the minimum Beta values for the device, not the typical. As this is a darlington pair device, the value is going to be for the entire device, not simply for a single transistor within the device.

    For II -250uA beta(min) = 400

    For II -350uA beta(min) = 571

    For II -500uA beta(min) =700

    The beta values are going to increase with temperature. Also note that the device collector current will not exceed 500mA per channel, but the channels may put in parallel to drive larger currents.

    We suggest that you design with the minimum beta values in mind when considering your design.

    Best,
    Michael

  • 0 in reply to Michael J Schultis
    Guru 11235 points

    Hi Michael,

    Thank you for response.

    I understood the following information.
    1. "The variation in Beta values is very large between devices so it is difficult to give a typical value."
    2. " As this is a darlington pair device, the value is going to be for the entire device, not simply for a single transistor within the device."
    3. "The beta values are going to increase with temperature"

    I have a request.
    As reference, Are there Beta values of one sample at the following condition?
    * It is no problem that value is not guaranteed value.
    - 0C, 25C, 40C
    - 50uA, 250uA, 350uA, 500uA ,700uA

    I will inform this value as reference to my customer.
    and guaranteed value which we are able to suggest is only "Figure 8. Minimum Output Current vs Input Current" in datasheet.

    Thanks
    Shimizu

  • 0 in reply to masahiko shimizu
    TI__Mastermind 24985 points

    Hello Shimizu,

    The best that I have to share is the following for Vce = 1.5V and it is the entire Beta value for the device, not just a single transistor:

    50uA: Beta~=0 across temperature (0 - 40C)

    150uA: Beta ~= 1800 - 2600 across temperature (0 - 40C)

    Above 250uA for the device in question, the device output current typically saturates at Iout = 500mA

    Again, this is just a single device for Vce = 1.5V and as you mentioned, we cannot guarantee these values, and this could be far above what is typical for the device.

    Best,
    Michael

  • 0 in reply to Michael J Schultis
    Guru 11235 points
    Hi Michael

    Thank you for your support.
    I understood.
    It was very helpful.

    Thanks
    Shimizu
  • 0 in reply to masahiko shimizu
    TI__Mastermind 24985 points
    Shimizu,

    Always happy to help however we can.

    Best,
    Michael