600 V depletion-mode MOSFET in a SOT-23
The BSS126H6327XTSA2 is an N-channel depletion-mode MOSFET with 600 V drain-source voltage and 21 mA continuous drain current. It conducts at zero gate voltage and requires a negative Vgs to turn off.
On-resistance and drive voltage — what 500 Ohm at 16 mA tells you
The maximum on-resistance is 500 Ohm at a drain current of 16 mA and Vgs of 10 V. This is not a low-Rds(on) power switch; the high resistance is inherent to the 600 V blocking capability in a small SOT-23 package. The drive voltage range is 0 V to 10 V, with the device fully on at Vgs = 0 V (depletion mode) and fully off at a negative Vgs below the threshold. For a linear current-source design, the 500 Ohm figure sets the minimum voltage drop across the device at a given current.
Temperature range and package — industrial and automotive-grade fit
The part is surface-mounted in a PG-SOT23 package (TO-236-3 / SC-59 compatible), which keeps the board footprint small but limits power dissipation to 500 mW at 25 °C ambient.