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TIC12400-Q1: Inquiry about ADC function of TIC12400-Q1

Part Number: TIC12400-Q1
Other Parts Discussed in Thread: TIC10024-Q1

Hi Team

I have some questions regarding ADC of TIC12400-Q1.

1. Are the TIC12400-Q1 and TIC10024 the same except for the ADC function?

2. Are the TIC12400-Q1and TIC0024-Q1 the same except for the parameters that are responsible for the ADC functions?

3. When monitoring the voltage input to the ADC input pin of the TIC12400-Q1 in real time, let me know the ADC error rate range.

4. Is hysteresis determined if ADC input pin is Active Low (Low detect)?

5. If hysteresis is defined, how much is the hysteresis range?

6. I know that the ADC input pin can set the threshold voltage. Can the user set the hysteresis region for the threshold voltage?

    ┌──────── Example of hysteresis in question 6 ──────┐

    │   GND Switch Off detection threshold voltage = 5.0 V                 │

    │   GND Switch On detection threshold voltage = 4.3 V                 │

    └───────────────────────────────────┘

     Can you set the hysteresis range of 0.7V as shown in the example above?

     If so, please let me know how.

Thank you.

  • Hello Charles,

    1.  Correct, there is also some diagnostic features removed in the TIC10024-Q1 as well due to the ADC being removed.

    2.  Correct

    3.  We are working on adding this to the datasheet. If you need something immediately to evaluate the device let me kno

    4.  Can you elaborate a little more on this question? I don't follow what is meant by active low (low detect)

    5.  There is hysteresis on the comparator and ADC but it is impossible to measure or view because hysteresis requires that you remember the last measurement taken.

    For example the TIC12400-Q1 will cycle through the inputs sequentially, as the comparator/ADC measures the next channel it loses the previous measurement.  As it cycles back to measure the same channel in the next cycle, the previous measurement has been lost and an entirely new measurement will be taken making hysteresis impossible to measure or view.

    6. There's two ways to do this but it is not directly supported.

    a.  Use a raw ADC measurement for the channel and in software interrupt the raw ADC code as needed to fit the thresholds

    b.  Use a channel that supports 3+ switch states.  Set the lower and upper thresholds as needed and ignore the middle switch state.  E.g. if moving from 4. V to 4.5 V this will trigger a /INT but the MCU should ignore the change unless it reaches the third switch state which would be set at 5.0 V in your example.

    Option b is less software on the MCU but would use a multi-state channel for a single input.

    Regards,

    Andrew

  • Hi Andrew
    Thank you for quickly response.

    3. My customer want to use the real-time ADC in the TIC12400-Q1.
    So, if you have data for the ADC error rate, please share it.
    If you have information about the rate of error change with temperature change, please also share.

    4. Low detect means ground switching monitoring.
    Due to wetting current and line impedance, the voltage will float during ground monitoring.
    When the GND switching detection is detected, the voltage may float to above the comparator threshold specified in TIC12400-Q1.
    (Input pin voltage may be over 4V when switching GND due to the surrounding environment.)
    So they try to monitor the input state by adjusting the threshold voltage value using the ADC.
    For detect switch on/off at 5V, if I set the ADC at 853, I ask how hysteresis is set.

    Additional questions..
    7. What is the minimum Vs value for the ADC to operate correctly?

    Thank you.
  • Dear Andrew
    Please reply quickly.
    The customer is requested urgent because a tight schedule.
  • Hello Charles,

    Can you send me an email for more information on the ADC error rate: a-mason@ti.com.

    There will be no hysteresis if you set the ADC setting to 853.  You would have to do this in software and ignore changes until you saw the desired code change.

    The ADC will operate as specified across the voltage range in the recommended operating table, from 4.5 V to 35 V.

    Regards,

    Andrew

  • Hi Andrew

    The datasheet states that the ADC full scale range is 0 to 6V, and it outputs 10 bits (1023).
    As you said, if the ADC's operating range is 4.5V to 30V, what about the reference voltage?
    When the voltage of Vs is less than 6V, does ADC Ref Voltage become Vs?
    For example, if Vs is 4.5V (<6V), is INx_adc (max) = 4.5V = 1024?
  • Hello Charles,

    Internally we will generate our own stable reference that is independent of the supply voltage across the recommended supply range, including down to 4.5 V.  To be able to measure the input voltage from 0 V to 6 V we additionally scale down the input voltage so ensure that even at low supply we will not have headroom issues sampling the voltage.

    In the Functional Block Diagram in section 8.2 of the datasheet the resistors R1 and R2 scale down the input voltage.  So to answer your question, even at a VS of 4.5 V the ADC code 1023 will still represent 6 V at the input pin.

    Regards,

    Andrew

  • Hi Andrew

    TIC12400-Q1 Error rate data was requested by e-mail.
    I have not received a reply yet.
    Please checking and reply.
    My e - mail address is Charles.Jeon@wtmec.com

    Thank you!
  • Hello Charles,

    I am deeply sorry but it looks like the emails are getting screened.  I'm looking for a workaround and will update accordingly.

    Regards,

    Andrew

  • Please send TIC12400-Q1 ADC error rate data to Charles.Jeon@wtmec.com.
  • Hello Charles,

    I am unable to send/receive.  We are looking to add this to the datasheet and I'll have more information on a timeline tomorrow.

    Regards,

    Andrew

  • Hello Charles,

    We are still working on this. I apologize for the slow movement.

    Regards,
    Andrew