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TPS389006-Q1: Questions: 1.8V operation mode and threshold limits

Fabian Range
Prodigy 20 points
Part Number: TPS389006-Q1

Hello Team,

I have a few technical questions regarding the TPS389006-Q1, which I was not able to figure out with the preliminary dataheet.

In table 12-1 and -2 of the datasheet, I found some information regarding the under and over voltage threshold of the device. Does it mean, that the preliminary (pre-production) IC can only monitor voltages from 0.2-1.745V?
In our application we would need at least up to 3.3V.

Furthermore I have seen that the device is able to work with 1.8V and 3.3V interfaces. How to set this configuration? How to set DEV_CONFIG.SOC_IF1?
Is it right that you will offer different devices and the pre-production device features only 3.3V.

Can you give me some information about the timeline, when can you offer the mass production devices with 1.8V interface voltage?

Best regards,

Fabian

  • 0
    TI__Expert 5900 points

    Fabian,

    The IC can monitor from 0.2V to 5.5V. In the electrical table you can see a scaling factor which automatically changes to 4x when the threshold is set to higher than 1.475V.

    The pre-production IC are configured for 3.V I2C logic. Mass production will also be with 3.3v for the part. If 1.8V interface voltage is needed you can request samples with this change and we would have a separate orderable for this. 

    Regards,

    Mathew

  • 0 in reply to Mathew Jacob1
    Prodigy 20 points

    Hello Mathew,

    thanks for your answer.

    We proceed with our development and have some new questions:

    - do we need an external RC filter on the monitoring pins? On the first page there is written "User adjustable glitch immunity and hysteresis levels via I2C". But we can't find information how to set the hysteresis or glitch immunity. Where can we find it?

    - NIRQ pin: what is the default output function of this pin? Open collector or push pull? It is only written that both is possible. For operating with 1.8V interface open collector would be nice. How to reconfigure the output driver?

    - we would like to measure also bigger voltages (24V), but due to the input current of 20µA and the needed voltage divider the error would be too big. What does IMONX_ADJ Input current for ADJ version (1x) mean in the datasheet (page 6)? Is there an option of the IC with reduced input current, which can be used for higher voltage monitoring?

    Thanks,

    Fabian

  • 0 in reply to Fabian Range
    TI__Expert 5900 points

    Fabian,

    You do not need external RC filter on monitoring pins. Using I2C commands you can setup glitch immunity on following registers.

    0x24 for MON1, 0x34 for MON2, 0x44 for MON3, 0x54 for MON4, 0x64 for M0N5, 0x74 for MON6

    These registers are in bank 1; to enter bank 1 you need to write 01(data-hex) to register f0

    Hysteresis is not user adjustable but will vary depending on the voltage thresholds set for OV/UV faults.

    Hysteresis is 5mV for voltages in 0.2V to 1.475V

    10mV for 1.48V to 2.95V

    and 20mV for >2.95V

    NIRQ pin default is open drain/collector

    The input current for the ADJ version is 0.1uA max. You would need to order the adjustable option. The orderable for the ADJ version is

    TPS389006ADJRTERQ1  ,pre production samples is PPS

    Regards,

    Mathew

  • 0 in reply to Mathew Jacob1
    Prodigy 20 points

    Hi Mathew,

    thanks again, this already helped a lot. One hopefully last question:

    What does (1x) mean? Is that only one pin which have 0.1µA input current or does all pins feature this?

    Thank you,

    Fabian

  • +1 in reply to Fabian Range
    TI__Expert 5900 points

    For the ADJ version all IMON pins have 0.1uA. 1x refers to the scaling always 1 since there are no internal resistors.

    Mathew

  • 0 in reply to Mathew Jacob1
    Prodigy 20 points

    Perfect thanks understood, thanks for your help

    Fabian