• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 49 subscribers
  • Views 684 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

LM2901: About VICR

Kenji Ohno1
Genius 5095 points
Part Number: LM2901

Hi Teams,

My customers have questions on setting up VICR.

The following specifications are Min = 0 to Vcc - 1.5V at 25℃

For example, when Vcc = 2 V, the Min specification becomes 0 to 0.5 V, but at that time, VICR is 1 V.

Is this out of range?

Does the problem occur?

In full range, it is 0 to Vcc - 2V. Does temperature change affect both high temperature and low temperature?

Best Regards

Kenji

.

  • 0
    Guru 140200 points

    Hi Kenji,

    the common mode input voltage range of LM2901 is 0V...Vcc-1.5V. So, with Vcc=2V an input voltage of 1V exceeds the common mode input voltage range of LM2901.

    Kai

  • 0 in reply to kai klaas69
    Genius 5095 points
    Kai-san,

    Thank you for answering.

    Dear TI Team member

    I appreciate your support.
    Temperature vs. Voltage Range Change Curve data not available?
    VICR specifications are 0 V to VCC - 1.5 V @ 25 ° C, 0 V to VCC - 2 V @ full range.
    I would like to know the amount of change due to temperature.

    If the specification of VICR is out of order, could you tell me the principle of operation in which the high / low output is inverted?

    Best Regards,
    Kenji
  • 0 in reply to Kenji Ohno1
    Guru 140200 points
    Hi Kenji,

    this is explained in section 9.2.2.1 of datasheet.

    Violating the common mode input voltage range can also slow down the comparator.

    Kai
  • 0 in reply to kai klaas69
    Genius 5095 points
    Dear TI member,

    Is there data that is the basis for temperature change?

    BestRegards,
    Kenji
  • 0 in reply to Kenji Ohno1
    TI__Mastermind 49966 points

    Hello Kenji,

    The VICR changes typically -4mV/°C.

    So the upper input common mode range will decrease as the temperature decreases.

    At cold, the VICR range is typically to (VCC-1.6).

    At room temp, the input threshold range is typically to (VCC-1.4).

    At hot, the range is typically to (VCC-1).

    Consequently, the lower VICR moves closer to 0V as the temperature increases.

    Note that inputs below -0.3V is violating Abs Max and possible reversals could occur at high temp when below 0V.

    Of course, we recommend staying within the specified limits!