Pre-biased NPN in a tiny SOT-883 package
The BCR 135L3 E6327: The Infineon BCR 135L3 is an NPN pre-biased digital transistor with two integrated resistors (10 kΩ base, 47 kΩ emitter-base) that eliminate the external bias network. The SOT-883 (PG-TSLP-3-4) package handles collector currents up to 100 mA and blocks 50 V, with a transition frequency of 150 MHz.
Active production — no obsolescence headache
Infineon lists the BCR 135L3 as Active.
Package and mounting
Saturation voltage is specified at 300 mV maximum with 500 µA base current and 10 mA collector current — well within the Vce(sat) budget for a typical low-side switch driving a relay coil or an LED string. The 100 nA collector cutoff keeps leakage negligible at high temperature, which matters if the load is a high-impedance input.
