SBD Selection for S6BP501A and S6BP502A – KBA224896

Version 3

    Author: AtsushiT_61           Version: **

     

    Question:

    How can I select Schottky Barrier Diode (SBD) for S6BP501A and S6BP502A?

     

    Answer:

     

    The required VF criteria of the SBD is as follows:

                        1.png

    Where, VUVLO_SHDN = 4.4 V(max)

    1 Check the above VF value at the following condition of forward current

    2.png

    When VOUT5V reaches the output setting voltage of 5 V, S6BP501A (or S6BP502A) turns OFF the internal regulator REG between VINVB terminals and uses the voltage from VOUT5V to maintain the switching operation. Then, the voltage dropped by VF from the VOUT5V output is applied to the VB and VDD pins. If SBD with higher VF is used, VB and VDD voltages for controlling the switching operation cannot be maintained, and under voltage lockout (UVLO) of the VB function stops the switching operation. Note that SBD with lower VF is necessary to avoid UVLO detection.

    Figure 1. Connection of SBD