Questions about igbt module

Discussion in 'Homework Help' started by jm-a, Dec 5, 2010.

  1. jm-a

    Thread Starter Active Member

    Oct 20, 2010

    I have a few questions about igbt module, if someone could reply, it would be great :)

    Data about components to check my values:

    BSM10GD120DN2 ( igbt module from eupec )

    DC Collector current T°c= 25 ° Ic=15A
    T°c= 80°c Ic=10A

    Vge Threshold 5,5 V typical
    4,5 V mini

    Pulse collector current tp=1ms 30A for T°c = 30A
    20A T°c = 80°

    FOD3120 ( optocoupler from Fairchild )

    " Absolute Maximum Ratings " Io Peak Peak Ouptut current 3A

    MEA1D1509SC ( dc/dc converter )

    Output 18V and +- 56 mA

    First question:

    Gate Resistor Value ( From AN 7003 p6/10 Gate resistor-Principles and application )

    Rg mini = ( Vg on -Vg off ) / IGm

    Vg on = 18V
    Vg off = Threshold voltage for BSM10GD120DN2 is about 4,5V mini, so my choice is 4V . Right or wrong ?

    Io Peak Maximum Current for FOD3120 is 3A

    Rg mini = ( 18 - 4 ) / 3 ≈ 5 Ω Right or wrong ?

    Second question:

    Now i need to power an inductive load ( brushless ) with 5A average current.

    First: check if V positive rail is about 0,8 Vce in maximum ratings.

    Then rough estimate: surge current is about 6 x average current, so I must see Pulsed collector current in the data.

    Value is about 30A, so it's ok. Right or wrong?

    I only want to know if surge current time is generally , in 1 mS or more?
    Any idea?

    Third question ( Extracted from Fuji IGBT module application manual p 22 /95 )

    " On an installed IGBT , if the gate circuit is faulty or inoperative ( while the gate is open ), the IGBT may be destroyed when a voltage is applied to the main circuit.

    In order to prevent this destruction, it's recommended to add, between gate and emitter:

    - resistor Rge
    - diode - avoiding overvoltage, i think ? - and how to choose this component ? TVS bidirectionnal diode or other?
    - capacitor value of 10 % of Cge

    One more thing i don't understand, these added components are mandatory in all design cases or only for " pcb + wire feed " ------> IGBT bricks?

    Is it the only way to do the job ?

    Thanks a lot.

    Last edited: Dec 5, 2010