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LTC4417

Hi, I am MURALI SELVAM and LTC4417 IC using in my project. I have one doubt. How to calculate (R1, R2, R3 UV1-OV1), (R4, R5, R6 UV2-OV2),  (R7, R8, R9 UV3-OV3) My supply range is 3 inputs are same range UV-4 Working-5 OV-5.7 Voltages. With internal Hysteresis 30mV.  How to define IOVUV(HYS) between 50nA ≤ IOVUV(HYS) ≤ 500nA or else in the datasheet where the formula was mentioned. Kindly give me the answer as soon as possible. Thank you



typing mistake
[edited by: MURALIPALANI at 7:30 AM (GMT -4) on 22 Mar 2024]

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    •  Analog Employees 
    •  Super User 
    Mar 22, 2024 +1 verified
    How to define IOVUV(HYS) between 50nA ≤ IOVUV(HYS) ≤ 500nA or else in the datasheet where the formula was mentioned.

    From page 12 in the datasheet:


    An RHYS of 124kΩ gets you an I

    •  Analog Employees 
    •  Super User 
    Mar 28, 2024 in reply to MURALIPALANI +1 suggested
    How to calculate R1, R2, R3 for (UV1-OV1), R4, R5, R6 for (UV2-OV2),  R7, R8, R9 for (UV3-OV3) My supply range is 3 inputs are same range UV-4 Working-5 OV-5.7 Voltages. With internal 
  • How to define IOVUV(HYS) between 50nA ≤ IOVUV(HYS) ≤ 500nA or else in the datasheet where the formula was mentioned.

    From page 12 in the datasheet:


    An RHYS of 124kΩ gets you an IOVUV(HYS) of 500nA, while 1.24MΩ gets 50nA.

  • How to calculate R1, R2, R3 for (UV1-OV1), R4, R5, R6 for (UV2-OV2),  R7, R8, R9 for (UV3-OV3) My supply range is 3 inputs are same range UV-4 Working-5 OV-5.7 Voltages. With internal Hysteresis 30mV.

    Would you explain me above mentioned question?

  • How to calculate R1, R2, R3 for (UV1-OV1), R4, R5, R6 for (UV2-OV2),  R7, R8, R9 for (UV3-OV3) My supply range is 3 inputs are same range UV-4 Working-5 OV-5.7 Voltages. With internal Hysteresis 30mV.

    GIVEN: internal 30mV hysteresis:

    UVTH(FALL)=1V
    OVTH(RISE)=1V
    UVTH(RISE)=1.03V
    OVTH(FALL)=0.97V

    WANT:

    UVFALL=4V
    OVRISE=5.7V

    Choose bias current at OVRISE so the sum of RTOP, RMID, RBOT are ~1MΩ.

    RSERIES=RTOP+RMID+RBOT=1.14MΩ
    IBIAS=5uA

    FIND RBOT:

    RBOT=OVTH(RISE)/IBIAS
    RBOT=1V/5uA=200kΩ

    FIND RMID:

    RMID=[{UVTH(FALL)/UV(FALL)}*RSERIES]-RBOT
    RMID=[{1V/4V}*1.14MΩ]-200kΩ
    RMID=85kΩ
    [Use standard value of 84.5kΩ]

    FIND RTOP:

    RTOP=RSERIES-RMID-RBOT
    RTOP=1.14MΩ-85kΩ-200kΩ
    RTOP=855kΩ
    [Use standard value of 845kΩ]

    Simulate in LTspice to confirm the UV-OV window.