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AUIR3241S reverse battery protection

AUIR3241S reverse battery protection

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AUIR3241S reverse battery protection, additional diode required on the datasheet block diagram

  • AUIR3241 is targeted to the applications such as power switch for stop and start board net stabilizer and battery switch, for example.
  • In the datasheet (Rev 1.01, 2017-09-12), three application block diagrams are introduced for back to back, Q diode, and battery switch.  In this KBA, back to back block diagram is used as an example for the explanation.
  • The typical normal connection (back to back) used in the datasheet is shown as the figure 1.
  • If reverse battery situation happens, the path through K1 body diode is the critical path (See the figure 2 and figure 3) and must be protected from the device destruction.
  • To solve it, the inverse current into K1 body diode needs to be blocked (see the diode D1 in the green rectangular in the figure 4: the diode rating is at least 100V / 200mA).

Figure 1: typical normal connection (back to back)


Figure 2: reverse battery situation and the critical current path


Figure 3: reverse battery situation and the critical current path in details


Figure 4: reverse battery situation and the solution for the critical current path

More information

  • For additional documentation please refer to the gate driver ICs product page