SLVAG00 January   2026 BZX84C15V

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Zener Operation and Key Parameters
    1. 2.1 Operation
      1. 2.1.1 Device Operation Under Breakdown
    2. 2.2 Key Parameters
  6. 3Zener Diode Manufacturing Process
    1. 3.1 Manufacturing
      1. 3.1.1 Wafer Fabrication
      2. 3.1.2 Complete Manufacturing Flow
      3. 3.1.3 Process Control and Capability
  7. 4Why Choose TI Zener Diodes?
  8. 5Selecting the Correct Protection Diode
    1. 5.1 Zener Diode
    2. 5.2 ESD Diode
    3. 5.3 TVS Diode
  9. 6Typical Applications
    1. 6.1 Zener Diode
      1. 6.1.1 Voltage Regulation
      2. 6.1.2 MOSFET Gate Overvoltage Clamping
      3. 6.1.3 CAN Bus Overvoltage Protection
    2. 6.2 ESD Diode
    3. 6.3 TVS Diode
  10. 7Summary
  11. 8References

6.1.2 MOSFET Gate Overvoltage Clamping

In this example we select a zener diode to prevent an enhancement mode N-channel MOSFET's gate-to-source maximum voltage rating from being exceeded. The input voltage is 12V with a 1A maximum load current condition. The chosen MOSFET Q1 is CSD16401Q5. From the MOSFET datasheet, it specifies a 1.5V typical threshold voltage (Vgs,th) for turn-on. The absolute maximum rated gate-to-source voltage (Vgs) is specified as 16V, therefore we must limit the gate voltage to less than 16V. In order to provide sufficient design margin an 8.2V nominal zener voltage is selected. The chosen D1 zener diode is BZX84WC8V2, as shown in Figure 6-5. Similar to the voltage regulation application example above, maximum power dissipation should be calculated to ensure the package rating is not exceeded.

MOSFET Gate Overvoltage Clamping Final Circuit Figure 6-5 MOSFET Gate Overvoltage Clamping Final Circuit