Pre-biased NPN for digital output banks
The Infineon BCR521E6327HTSA1 is a pre-biased NPN transistor in a SOT-23-3 package, integrating two 1 kΩ resistors (base and emitter-base) so that a single component replaces the transistor plus two external passives. With a 500 mA collector current rating and 50 V Vce breakdown, it handles typical low-side switching for relays, solenoids, indicator LEDs, and logic-level interface circuits in industrial controls and consumer appliances. The 100 MHz transition frequency keeps switching edges clean for PWM dimming or low-speed serial buses.
Saturation voltage and drive margin
Vce saturation is specified at 300 mV maximum with a 2.5 mA base current driving 50 mA collector current. The minimum DC current gain of 20 at 50 mA, 5 Vce confirms the pre-biased divider delivers enough base drive for the rated collector current.
Last Buy — what it means for procurement
The BCR521E6327HTSA1 carries a Last Buy lifecycle status. This is the final procurement window before the part is discontinued. Buyers should evaluate their remaining lifetime demand and place a last-time buy order to cover production needs. For new designs, a pin-compatible pre-biased NPN from the same SOT-23-3 footprint family should be qualified as the forward-looking alternative.
Package and power dissipation
Housed in the industry-standard SOT-23-3 (PG-SOT23) surface-mount package, the part dissipates up to 330 mW. The 100 nA maximum collector cutoff current ensures negligible leakage in off-state, important for battery-powered or low-standby designs.