• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Subscribers 33 subscribers
  • Views 611 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ULN2003A internal register

hisakichi kobayashi
Intellectual 950 points
Other Parts Discussed in Thread: ULN2003A

Hi all,

Although the data-sheet of ULN2003A was read and it was worrisome,
Would you teach the individual variation of internal resistance,
and temperature characteristics?
 Example:
  R1:2.7komega±30% (300 ppm)
  R2:7.2komega±30% (300 ppm)
  R3:3.0komega±30% (300 ppm)

Best Rerds,
Hisa Kobayashi.

  • 0
    TI__Guru**** 165316 points

    Hisakichi-san,

    The resistors are expected to be +/-15% and +1500ppm/C.
    The variances affect all three resistors the same.
    For example; If one resistor is +5% then all three will be +5%.

    I can check to see if ULN2003A meet your needs.
    What is application's input VIL and VIH?
    What is application's maximum output current?
    How many channels turned on at same time?
    What is value of load power supply voltage?

  • 0 in reply to Ron Michallick
    Intellectual 950 points

    Hi Ronald-san,

    The input of application is 3.75V.
    The maximum output current of application is 400 mA.
    The number of channels of application is two.
    A temperature span is set to -20C ~ 70C.

    Regerds
    Hisa kobayashi

  • 0 in reply to hisakichi kobayashi
    Intellectual 950 points

    Hi Ronaid-san,

    It is additional information.
    As for load power service voltage, 14V is the maximum voltage.
    The load minimum is 33.7ohms.

    Best Regerds,
    Hisa Kobayashi.

  • 0 in reply to hisakichi kobayashi
    TI__Guru**** 165316 points

    Hisakichi-san,

    3.75V input is more than enough drive to ensure a saturated driver. No problems here.
    The only concern to check is internal die heating.

    I suggest using three channels for one load and three or four channels for the second load.
    At 14V and 33.7 ohms, max current per channel is (14V-1V)/33.7 ohms / 3 = 129mA

    Using "D" SOIC package TJA = 73C/W, TA=70C, TJ[max] = 125C and typical 125C performance, gives a maximum current per channel (6 channels active) of 159mA.

    Using "PW" TSSOP package TJA = 108C/W, TA=70C, TJ[max] = 125C and typical 125C performance, gives a maximum current per channel (6 channels active) of 118mA.

    Therefore, I recommend the "D" package ("NS" and "N" are also acceptable)
    The "PW" will typically run above 125C at worst load and highest TA.

    The ULN2003 can run up to Tj=150C, but will have better long term reliability when 125C or less.

  • 0 in reply to Ron Michallick
    Intellectual 950 points

    Hi Ron.

    Thank you for the best reply.
    For the time being, It proposes making three channels into one.

    Regards,
    Hisa Kobayashi.