800 V MOSFET in a TO-92 – the auxiliary-supply workhorse
The STQ1NK80ZR-AP: It is built for off-line auxiliary supplies, flyback converters, and bias rails where the primary switching transistor sees the full rectified DC bus.
Rds(on) and gate drive – sizing the conduction loss
The 3 W package limit in the TO-92-3 means thermal management is tight. Gate charge is 7.7 nC at 10 V, and input capacitance is 160 pF at 25 V drain-source – light enough that a simple gate-drive resistor from a PWM controller can switch it without a dedicated driver.
Temperature grade and package – through-hole simplicity
The TO-92-3 through-hole package with formed leads is hand-solderable and fits standard prototyping boards. Maximum gate-source voltage is ±30 V, which gives margin against ringing on the gate node in a hard-switched topology.