• State
  • Locked Locked
  • Replies 6 replies
  • Subscribers 62 subscribers
  • Views 84 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LM74700DDFEVM: Ideal Diode Controller requirement

Rajkumar Chaurasiya
Prodigy 120 points
Part Number: LM74700DDFEVM
Other Parts Discussed in Thread: LM74502, LM74701-Q1, LM74721-Q1, LM74700-Q1, LM74800-Q1, LM74502-Q1

Tool/software:

Hi TI Expert,

I need to select Ideal diode controller for reverse current protection for both battery and power supply source. 

I need two ideal diode controller, one for single MOSFET Q1 drive for revers current protection and other driving back to back MOSFET's Q2 and Q3 for battery reverse current protection and load disconnection from battery.

Can you please suggest the suitable Ideal diode controller. Currently I am using LT4372 Ideal diode controller. I want to replace with TI ideal diode controller.  So please suggest as per below diagram.

I have selected two ideal diode controllers- 

1. LM74700 for MOSEFT Q1 drive 

2. LM74502 for MOSFET Q2 & Q3 drive

I will not use TVS diode. So please suggest without TVS diode.

Please see the below diagram.

Regards,

Raj Kumar

  • 0
    TI__Mastermind 18480 points

    Hi Rajkumar,

    If you want reverse current protection in both the paths, please find the recommendation below.

    LM74701-Q1 for Q1 drive.

    LM74721-Q1 for Q2 and Q3 drive.

    These are fully TVS-less operation ideal diode controllers for a set range.

    Please help me understand your requirements for transient protection. What level of transients do you expect? both positive and negative.

    Regards,

    Shiven Dhir

  • 0 in reply to Shiven Dhir
    Prodigy 120 points

    Hi Shiven,

    Thanks for reply.

    Transients levels can be maximum 40V on both negative and positive side.

    Regards,

    Raj kumar

  • 0 in reply to Rajkumar Chaurasiya
    Prodigy 120 points

    Hi Shiven,

    I am not conformable to use LM74721-Q1 because of extra components like inductor etc. Can you please suggest other parts.

    What is the difference between LM74700-Q1 and 74701-Q1?

    Why can not use LM74700 for Q1 MOSFET drive?

    Why can not use LM74502 for Q2 & Q3 MOSFET's drive?

    Please provide your feedback.

    Regards,

    Raj Kumar

  • 0 in reply to Rajkumar Chaurasiya
    TI__Mastermind 18480 points

    Hi Rajkumar,

    Since you asked for a TVS-less controller, I recommended LM74701-Q1 and LM74721-Q1.

    You can use LM74700-Q1 as well but will need an extra TVS.

    To replace LM74721-Q1, you can use LM74800-Q1.

    LM74502-Q1 can't be used since it does not offer reverse current blocking.

    Regards,

    Shiven Dhir

  • 0 in reply to Shiven Dhir
    Prodigy 120 points

    Hi Shiven,

    LM74800-Q1 is TVS-less or with TVS? Is it compulsory to use TVS diode?

    Any other part number for Q2 & Q3 (back to back N Channel MOSFET) drive with TVS and without TVS?

    LM74701-Q1 is for Q1 drive (single MOSFET drive). But I am concern about q2 & Q3. 

    With TVS IC, only TVS will add. Right? Can you please one with TVS for Q2 & Q3 drive.

    I am wary about external components like inductor in LM74721-Q1 and TVS in LM74800-Q. I want go with minimum external components because of the PCB size constraint.

    Please provide your suggestions.

    Regards,

    Raj Kumar

  • 0 in reply to Rajkumar Chaurasiya
    TI__Mastermind 18480 points

    Hi Rajkumar,

    LM74800-Q1 requires a TVS. TVS is required to keep the MOSFET and controller safe. If the max transient on you expect is -40V, TVS is not really required if nominal VIN max is <20V. (for a 60V VDS FET)

    You can use LM74800-Q1 to drive Q2 and Q3.

    Regards,

    Shiven Dhir