Pre-biased NPN in a small SC-70 package
It includes a 10 kOhm base resistor (R1) and a 10 kOhm emitter-base resistor (R2), eliminating the need for two external resistors on the board. The SC-70 (SOT-323) package suits space-constrained, surface-mount designs.
Obsolete — sourcing from the spot market
Infineon has ended production, so the only available stock is surplus or excess inventory held by independent distributors. If you need a drop-in replacement, look for other NPN pre-biased transistors in the SC-70 package with the same 10 kOhm / 10 kOhm resistor configuration — the BCR133 family shares the same base number, but each suffix variant may differ in package or resistor values.
130 MHz transition frequency and saturation characteristics
With a transition frequency of 130 MHz, this transistor can handle switching applications up to the low-MHz range, suitable for relay drivers, LED switching, and level translation. The Vce saturation voltage is specified at 300 mV maximum at 500 µA base current and 10 mA collector current — a low enough drop to keep power dissipation manageable. The 250 mW maximum power rating in the SC-70 package means derating is needed for continuous operation near the current limit.