Ciss value high Gate value

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Dine_infin
Level 3
Level 3
Distributor
50 sign-ins First like received 10 questions asked

Dear team ,

We are comparing two devices for IPB020N10N5LF  and IPB020N10N5  for BMS design rating 14S / 60 . We are planning use 12MOSFET per board. 

1. we come across the  Ciss value too low i.e. Input capacitance  Ciss - Typ- 650  Max- 840 pF (  IPB020N10N5LF) Vs Input capacitance Ciss - Typ-12000 Max-15600 pF. 

2. for Gate Resistance  Gate resistance1) RG - typ- 44  Max 66 Ω (  IPB020N10N5LF) Vs Gate resistance  RG - typ-1.3 Max 2 Ω (IPB020N10N5). 

Pls. help to advice for Too Low value  Ciss and  High value in Gate Resistance IPB020N10N5LF is it correct?. 

last but not the least , Do we consider  IPB020N10N5LF Vs IPB020N10N5 for 6 Parallel MOSFET condition. 

BR 

Dine

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1 Solution
cynic_bandera
Employee
Employee
5 questions asked First question asked 100 sign-ins

LF has much bigger Ciss and Crss, it´s not targeted for switching applications. It has wide SOA and is targeted for BMS, hot-plug, and so on applications where wide SOA must have. OptiMOS has the best switching performance and low switching losses, but it can´t operate in the mentioned applications because they easily got damaged out of SOA.

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7 Replies
cynic_bandera
Employee
Employee
5 questions asked First question asked 100 sign-ins

LF has much bigger Ciss and Crss, it´s not targeted for switching applications. It has wide SOA and is targeted for BMS, hot-plug, and so on applications where wide SOA must have. OptiMOS has the best switching performance and low switching losses, but it can´t operate in the mentioned applications because they easily got damaged out of SOA.

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Dine_infin
Level 3
Level 3
Distributor
50 sign-ins First like received 10 questions asked

Hi  Cynic , 

Thank you for sharing low Ciss advantage.  

1. Can you we  help advice  for high  Gate resistance? i.e.  for Gate Resistance  Gate resistance1) RG - typ- 44  Max 66 Ω (  IPB020N10N5LF) Vs Gate resistance  RG - typ-1.3 Max 2 Ω (IPB020N10N5) ?

BR 

Dine

 

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It´s the integrated gate resistance. It defines the maximum switching speed of the MOSFET.

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Dine_infin
Level 3
Level 3
Distributor
50 sign-ins First like received 10 questions asked

Ok, but when using higher gate resistance, switching time becomes longer. As effect of switching loss increases and heat is generated. Does this high Gate resistance will effect overall system power loss. 

BR 

Dine

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It doesn't affect loss increase since in BMS MOSFETs operate in a static state, normally not switching.

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Dipti_Kiran
Moderator
Moderator
Moderator
250 sign-ins 10 likes received 50 replies posted

Hi @Dine_infin ,

Apologies for delay in response.

The BMS application restricts you to use LF MOSFETs, which are safer to use in this application due to their wider SOA and high integrated gate resistance.  In comparison to OptiMOS,  OptiMOS will provide the best switching performance and the lowest switching losses; nevertheless, we cannot use OptiMOS in this application since it will get out of SOA and easily damage the device.

Regards,

Dipti

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Dine_infin
Level 3
Level 3
Distributor
50 sign-ins First like received 10 questions asked

Hi Dipti , 

Thank you ,,,

BR 

Dine

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