Dual pre-biased NPN in SC-74 — last-time-buy status
The Infineon BCR523UE6327HTSA1 is a dual NPN pre-biased transistor pair in a single SC-74 (SOT-457) surface-mount package. Each transistor integrates a 1kΩ base resistor (R1) and a 10kΩ emitter-base resistor (R2), eliminating the need for external bias resistors in saturated switching circuits. Collector current is rated to 500mA with a collector-emitter breakdown voltage of 50V and a power dissipation ceiling of 330mW. Transition frequency hits 100MHz, and saturation voltage is 300mV max at 2.5mA base, 50mA collector. Typical applications include relay drivers, solenoid drivers, lamp drivers, and general-purpose logic-level load switches where board space is tight.
Last-time-buy — sourcing window closing
Infineon has placed the BCR523UE6327HTSA1 into last-time-buy (LTB) status. This means the final order window is open now; once it closes, the part will no longer be manufactured. For BOM lines that still need this specific dual pre-biased transistor, the window to commit is finite. Buyers should evaluate remaining lifetime demand and secure inventory before the LTB deadline passes.
Integrated bias resistors simplify the BOM
The built-in 1kΩ base resistor and 10kΩ emitter-base resistor per transistor mean this part turns on with a logic-level signal and turns off reliably without external components. That saves two resistors per channel — four total versus a discrete transistor pair — and shrinks the placement count. With a minimum DC current gain (hFE) of 70 at 50mA, 5V, it drives loads like relays and solenoids directly from a microcontroller output.