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LTM8052 output energy recuperation

Question asked by Michael_KWE on Jul 23, 2018
Latest reply on Aug 14, 2018 by Michael_KWE

Hi support team,

 

Suppose the input voltage is 28V, the output voltage is 18V, and there is a large (500 uF) capacitor at the output. Now, the output voltage is made to decrease to 12V by controlling the feedback. The questions are:

 

1. What is the discharge current of the capacitor that will be sinking into the power module? The pre-set current limit, or something else?

 

2. There is, of course, an input bulk capacitor as well. It is my understanding that the energy will flow from the output capacitor to the input capacitor via the power module. But, since the output voltage is less than the input voltage, the power module will work as a boost converter from output to input. Is this correct?

 

3. The power module will be the only load in  the system, so I'll need to take care about the output energy being released. The input voltage will be provided by a regulated power converter (Vicor or similar). I'm going to connect an isolating diode between this power converter and the LTM8052, and place a large capacitor at the input of the latter, so as to let the input voltage to rise (say, to 32V) while storing the output energy. The diode will not conduct in this case until the energy excess stored in the input capacitor has been eventually consumed. Thus, a recuperation mechanism will be created. Do you see anything wrong about this idea?

 

Thanks in advance and best regards,

Michael

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