LTM4650A EXTVCC

Dears.

I have two inquiries regarding LTM4650A.

Q1.
How should the EXTVCC of the LTM4650A be designed under the following conditions?

Case#1
VIN 12V, Vout 3.8V

Case#2
VIN 5V, Vout 3.8V

Q2.
In the schematic, SGND and GND are connected.
However, in DC2603A-A - Design Files's, Pin-C7 and Pin-D6 are connected.
but C7 and D6 are not connected to F7, F6, G7 and G6.

You need to check if the schematic is correct or if the DC2603A-A - Design Files's is correct.

Please check and let me know.

Thank you

Parents Reply Children
  • 0
    •  Analog Employees 
    on Apr 15, 2021 3:34 PM in reply to Henry J

    Hello Henry J,

    if you read the first screenshot from the pin description in my earlier answer you have your answer on question 1:

    VIN must be applied before EXTVCC, and EXTVCC must be removed before VIN.

    This statement is valid if VIn and EXTVCC are fed from different sources.

    EXTVCC connected to GND should have no impact, but I do not know the internal setup. As long as EXTVCC is below 4,7V the input is not used.