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  • TI Thinks Resolved

ATL431: ATL431 disable

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Replies: 3

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Part Number: ATL431

Hello support team,

In ATL431 datasheet Fig4, when VKA=VREF=0V, is IKA current same as Ioff :0.05uA?  If VREF is pulled low, can ATL431 be disable with very low current?

Customer would like to investigate ATL431 as over voltage cramp circuit, however, they need very low Iq (<1uA) during normal operation without over voltage.

Thanks,

Koji Ikeda

  • Hi Koji,

    I can help you with this request.

    Q1:  "In ATL431 datasheet Fig4, when VKA=VREF=0V, is IKA current same as Ioff :0.05uA?"

    A1: Yes as long as VREF is GND the leakage from VKA will be low. Keep in mind that the ATL431 is a analog device and as VREF is closer to 2.5V the leakage will increase like in figure 4.

    Q2:  "If VREF is pulled low, can ATL431 be disable with very low current?"

    A2: Depends how low it is. Figure 4 shows the leakage with different VREF currents.

    What is the voltage trip point?

    Will the system be operating near the trip voltage?

    -Marcoo

    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    If you feel your thread is resolved, please selected Answered.

    Looking for the lowest noise voltage reference? Check out the new REF70  family of products starting with the REF7025 with 0.22 ppm p-p of noise.

    Check out: Voltage Reference Design Tips For Data Converters a new app note that discusses voltage reference error and how it affects ADCs/DACs

  • In reply to Marcoo Z:

    Hello Marcoo-san,

    Thank you for your support. E.g. they would like to use nominal voltage 3.3V and over clamp voltage is around 4V. During 3.3V, the current have to be below 1uA, so they can't accept Fig.4 performance. My question is,

    Can ATL431 disable with Ioff, by VREF:0V, during 3.3V applied to Vanode?

    Thanks,

    Koji Ikeda

  • In reply to Koji Ikeda:

    HI Koji-san,

    Yes, the ATL431 will have Ioff if VREF = 0V from Vka = 0 to 36V. The current will increase as VREF increases.

    One other option would be the TPS3897A active-high supervisor but this is a 6uA to 12uA device.

    Another option would be a low Iq op amp (<1uA) and a REF1112 ( 1.2uA) device but this would be close to a 3-4uA solution.

    If this project is not urgent then we can talk over e-mail for future products.

    -Marcoo

    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    If you feel your thread is resolved, please selected Answered.

    Looking for the lowest noise voltage reference? Check out the new REF70  family of products starting with the REF7025 with 0.22 ppm p-p of noise.

    Check out: Voltage Reference Design Tips For Data Converters a new app note that discusses voltage reference error and how it affects ADCs/DACs

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