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Original question:

UCC21551-Q1: UCC21551-Q1

UCC21551-Q1: Quiescent current of IQ_DRIVER_VEE.

ALPHONS PULICKAN
Prodigy 50 points
Part Number: UCC21551-Q1
Other Parts Discussed in Thread: UCC21551

Tool/software:

For calculating Gate driver power supply ( UCC14240) requires IQ_DRIVER_VDD, IQ_DRIVER_VEE. But UCC21551 datasheet only has IQ_DRIVER_VDD. My VDD is 18V and VEE is -4V. 

  • 0
    Prodigy 50 points

    We are using the UCC14241 as the gate driver power supply IC and the UCC21551 as the gate driver. To calculate the power loss for RLIM1 and RLIM2 values (UCC14240), we need the quiescent current values without switching, specifically IQ_DRIVER_VDD and IQ_DRIVER_VEE. However, the UCC21551 datasheet only provides IQ_DRIVER_VDD. My VDD is 18V and VEE is -4V. Could you provide the data for IQ_DRIVER_VEE?.

  • 0 in reply to ALPHONS PULICKAN
    TI__Mastermind 23176 points

    Hi Alphons,

    Do you mean the UCC21551 VDD-VSS current? VEE is a pin on the UCC14241. VDD and VSS current should be equal and opposite when there is no switching. The quiescent current of UCC21551 will be between 1.2mA and 1.4mA, since the VDD-VSS=22V is between 15V and 25V.

    The supply current during switching will be Qg * f_sw, where Qg is the charge required to turn on the FET load.

    From the UCC14241 datasheet, Rlim will not need to conduct much current if one output is positive and the other is negative:

    Best regards,

    Sean