Tool/software:
Hello, is the Zener diode (D7) used in the bias supply path for VCCX correct? The voltage applied to the VCCX pin must never exceed 15 V, however, the zener voltage of D7 is 12 V.
The output voltage of the reference design is 15V, that means the Zener diode is conductive. Two 300 Ohm resistors in parallel (R16 and R11) limit the current to 100 mA (15 V / 150 Ohm).
Power dissipated over D7 = 100 mA * 12 V = 1.2 W
Zener diode used: BZT52C12T-7
- Max Pd = 300mW
1.2 W > 300 mW -> Zener diode goes up in flames.
Where am I wrong?
