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INA3221: INA3221 register 0F bit3-5

Part Number: INA3221

Hi team,

My customer wants to use the INA3221 in the system, we want to check how to clear the 0F register bit 3-5. Whether we can do and only can do with read the register 0F again?

  • Hey Frank,

    Well the datasheet states you can clear any warning or alert flags by reading the Mask/Enable register (0x0F). This seems to be the only way to do this.

    The CVRF can be cleared by reading the Mask/Enable register or by writing to the configuration register. So the datasheet states that this flag is the only thing that can be also cleared by writing to the configuration register.

    Best,

    Peter

  • Peter,

    Do you mean the INA3221 cannot get the alert information if the warning disappear? For example, channel 1 trigger the warning, when we read the register. The bit 3-5 are cleared. So we cannot get any information.. correct? Thanks.

  • Hey Frank,

    If any of the alert-flag indicator's are asserted in register 0x0F and then register 0x0F is read, then the asserted alert indicators are cleared. They will be asserted as soon as the corresponding measurement exceeds the alert level.

    So the normal operation is to look for an active-low signal from the Critical and Warning pin. If one of these pins goes active-low, then to determine which channel(s) exceeded the alert you would read the Mask/Enable register (0x0F). Once this register is read, the alert-indicator bits (CF1-3, SF, WF1-3) are cleared, but since you just read the register, the host should have the information to know which channel(s) exceeded the alert(s).

    If you do not want to miss any transient alert that does not last a long time, then you can set the mode of the Critical and Warning pins to latch mode in 0x0F register. By setting these pins to latch mode, once there is a measurement that exceeds its alert limit, the corresponding pin (Critical or Warning or both) will go active-low and then remain low so the host can come back to the INA3221 and determine which channel caused the alert-flag to be set.

    Sincerely,

    Peter