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MOSFET (Si/SiC) Forum Discussions

wph1995
Level 2
25 sign-ins 10 replies posted 5 questions asked
Level 2

Sorry if I didn't ask in the correct section.


I am designing an H bridge circuit to control a peltier cell, I use an IRFR3410TRPBF and a WCDSC006XUMA1 half bridge driver, I am putting an LC filter at the output of the H bridge and avoid noise in the peltier cell and I am calculating the value of the capacitor from
bootstrap, the problem I have is that the peltier cell consumes a current of about 8.12 A with a voltage of 24V, I put two 220uF capacitors in parallel in the LC filter, but I don't know if they will be damaged when it is in operation, I wanted put electrolytic SMD capacitors on it, but I'm afraid they'll explode, can the smd capacitors withstand the current of 8A? Or should I use other types of capacitors? and the other problem is that I want to put an SMD capacitor as a bootstrap and I'm not sure if it will withstand the current to turn on the MOSFET.
I would also like to know if there are Inifineon component libraries for use in Eagle and where I can download them.
thanks for your help


Excuse me, I forgot to tell you that I will control the peltier cell with PWM and that's why I use the LC filter

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sushank
Moderator
Moderator 50 replies posted 10 solutions authored 50 sign-ins
Moderator

Hi,

peak to peak ripple current you can calculate from your output inductor. using the V=Ldi/dt, here di is the peak to peak current value. and dt is the time taken from one peak to another peak, and V is the voltage drop across inductor during that period. Moreover you can also simulate the circuit in spice environment and check visually there. 

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sushank
Moderator
Moderator 50 replies posted 10 solutions authored 50 sign-ins
Moderator

Hi there, 

MLCC capacitors would be better for bootstrap application. Output stage capacitors should be designed based on the ripple current requirement and the holdup time requirement and not based on the continuous load current. Higher your filter inductance, lower will be your ripple current. So based on your design considerations, you may choose SMD MLCC capacitors output stage, if the ripple current is low. However to meet the required value of your design, you may have to use a series-parallel combination of several capacitors. Capacitor will come in action only when your DC/DC converter is halted and any ripple requirement from load side. Hopefully your DC/DC converter is 100% regulated. 

For EAGLE libraries, please check the respective package page. 

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wph1995
Level 2
25 sign-ins 10 replies posted 5 questions asked
Level 2

And how could I calculate the ripple current for the output voltage of a PWM controlled H-bridge working at 2.5KHz?

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wph1995
Level 2
25 sign-ins 10 replies posted 5 questions asked
Level 2

Peltier cells have approximately 2 or 3 Ohms as a maximum of resistance, is that value involved in the calculation of the ripple current?

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sushank
Moderator
Moderator 50 replies posted 10 solutions authored 50 sign-ins
Moderator

Hi,

peak to peak ripple current you can calculate from your output inductor. using the V=Ldi/dt, here di is the peak to peak current value. and dt is the time taken from one peak to another peak, and V is the voltage drop across inductor during that period. Moreover you can also simulate the circuit in spice environment and check visually there. 

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