Questions about LT8228

Hi ADIExpert

I have some questions about LT8228 application, may I have your suggestion for them

1. How does LT8228 change CC to CV mode and vice versa? couldn't find the description in the datasheet.

2. If I used 10 phases of LT8228 , and take each 5 phases as a group but the two groups have different Vin source, will this architecture works?

The difference I can think of is that each group would have different duty cycle, but I am not sure if there is any side effect.

3. if I used 10 pcs of LT8228 and seperate them as two groups of independent 5phases application,  connect the Vout of each group together, can they work in the CV and CC mode without problem?

4.Assume that 10 phases of  lt8228 are working in CC mode with total 50A output, can I set different constant current for each phase?

(ex: phase 1~3 : 9A for each phase, phase 4~6: 8A for each phase, phase 7~10:  12.25A for each phase)

any reply would be appreciated



  • 0
    •  Analog Employees 
    on Apr 6, 2020 2:31 AM 10 months ago

    Here are the answers:

    1. The part seamlessly transitions between CV and CC modes. Please refer to the block diagram on page 23 of the datasheet. You can see that there are two error amplifiers whose outputs are ‘ORed’ together. The lower output voltage is dominate.
    2. Yes, you can have a different input source and tie the outputs together. The current matching may not be as good while boosting, especially if you are regulating to two different voltages on the boost side. That is something you will need to evaluate.
    3. I don’t see the difference in this question from question 2. It will work.
    4. Yes, you can set different currents to different phases. The easiest way to do this is to just use a different RSET resistor value. It is possible to use digital POTs, although have not done this yet.