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[FAQ] What are the differences between ISO5851, ISO5852S, ISO5451 and ISO5452?

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Part Number: ISO5851, ISO5852S, ISO5451, ISO5452

What are the differences between ISO5851, ISO5852S, ISO5451, and ISO5452?

For what applications do the different features matter?

  • What are the Shared Features?

    ISO5451, ISO5452, ISO5851, ISO5852S are a family of single-channel isolated gate drivers targeting IGBT & SiC applications.  They are also offered in AEC-Q100 qualified variants.

    These devices are 2.5A/5A single channel isolated gate drivers with 5.7kVrms reinforced isolation

    Their shared feature set includes:

      • DESAT protection w/ Fault alarm
      • Miller clamp
      • Output Short-circuit clamp
      • Input & Output UVLO w/ “Power Good” ready indication

    How do the differences affect my choice?

    The specification differences are detailed in the table below.

      I​SO5451 I​SO5452 I​SO5851 I​SO5852S
    Output type Single Split-outputs Single Split-outputs
    VIORM
    Max Repetitive Peak voltage
    1420 VPK 2121 VPK
    VIOWM
    Max Working Voltage
    1420 VDC 2121 VDC
    1000 VRMS 1500 VRMS
    VIOTM
    Max Transient Isolation Voltage
    8000 VPK
    VIOSM
    Max Surge Isolation Voltage
    6250 VPK 8000 VPK
    Minimum CMTI 50-kV/μs 100-kV/μs
    Soft turn-off
    on DESAT Detection
    No Yes No Yes
    AEC-Q100 Available Yes

    Split Outputs

    ISO5852S and ISO5452 split the turn-on and turn-off paths while ISO5451 and ISO5851 are single-output drivers.

    With split outputs, separate external gate resistors can be used for each path without requiring the addition of a diode. This feature is especially beneficial for driving SiC FETs.

    Isolation Ratings

    ISO5851 & ISO5852S are rated to withstand higher working and repetitive peak voltages than ISO5451 & ISO5452. The choice depends on the bus voltage in the system.

    CMTI

    CMTI is an important parameter that affects every switching cycle. ISO5851 and ISO5852S are High-CMTI rated >100kV/us. This effectively increases resiliency against large dv/dt transients caused by hard switching.

    Soft turn-off

    ISO5452 & ISO5852S have STO on DESAT detection. During a short-circuit event, fast turn-off of the IGBT can cause a spike in VCE due to parasitic inductances. This VCE transient can be large enough to cause failure of the IGBT. STO “softly” pulls the gate low over 2us to prevent damage. STO is most effective when driving high-power IGBTs with longer short circuit withstand times


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