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TPS7B4250-Q1: Maximum Voltage VIN-ADJ

Basil
Intellectual 1620 points
Part Number: TPS7B4250-Q1

Dear Team,

is there a specified maximum voltage between VIN and ADJ for optimal operation?

Thanks and best regards,

B

  • 0
    TI__Guru 55940 points

    Hi B,

    TPS7B4250-Q1 will drive the internal pass fet so that Vout and Vadj are equal.  As such, Vin should be greater than or equal to Vout + Vdropout = Vadj + Vdropout in order for the output to achieve regulation.  For power efficiency, Vin should be as close to Vout + Vdropout as possible. 

    TPS7B4250-Q1 is a power dissipative device.  You can estimate the power dissipation as Pd = (Vin - Vout) x Iout.  This power will become heat and raise the junction temperature of the regulator.  Keep in mind that TPS7B4250-Q1 is designed, tested, and characterized for a junction temperature up to 150 C. 

    While thermal performance highly depends on application specific factors including layout, the thermal information table can be used as a first pass thermal calculation.  The thermal information table is modeled on a JEDEC Hi-K board.

    Tj = Pd x Rtheta_ja + Ta

    Very Respectfully,

    Ryan