LTM4644 use Question

We use LTM4644, VOUT1 and VOUT2 are in parallel, VOUT3 and VOUT4 are independent

We had few question about this.

1.Are FB1 and FB2 connected together? 

2.Are RUN1 and RUN2 connected together? 

3.Are SS1 and SS2 connected together? 

4.How to connect INTVCC1 and INTVCC2? 

5.How to connect PGOOD1 and PGOOD2? 

Is my follow connection correct?

  • +1
    •  Analog Employees 
    on Nov 23, 2021 8:29 AM

    Hi Getter,

    Fig. 37 in datasheet should be able to answer your questions 1 to 4 because typical circuit ties VOUT1 and VOUT2. Since both outputs are tied, you should be able to use either PGOOD pins to monitor output.

  • 0
    •  Analog Employees 
    on Nov 24, 2021 11:16 PM

    Hi Getter:

    As Fil mentioned, you can refer to Figure 37 for the connection. 

    1.Are FB1 and FB2 connected together?  -- Yes

    2.Are RUN1 and RUN2 connected together?  -- Yes

    3.Are SS1 and SS2 connected together?  -- Yes

    4.How to connect INTVCC1 and INTVCC2?  -- Not necessary. INTVCC is an output pin, a decoupling cap is needed on each INTVCC pin

    5.How to connect PGOOD1 and PGOOD2?  -- It can be shorted if channel 1 and channel 2 are paralleled. 

    Is my follow connection correct? -- Please double check the FB pin resistor setting. Datasheet page 10 provide the formula for parallel connection, the internal 60.4kohm should be divided by 2 if two channels are paralleled.