The Infineon BCR133SE6433BTMA1 is a dual NPN pre-biased transistor in a single SOT-363 package. Each transistor integrates a 10kOhm base resistor (R1) and a 10kOhm emitter-base resistor (R2), eliminating two external resistors per channel. This saves board space and reduces pick-and-place cost in high-volume designs where you need two low-current switching channels. Rated for a collector-emitter breakdown of 50V and a maximum collector current of 100mA, with a power dissipation ceiling of 250mW. The 130MHz transition frequency suits switching applications up to low-MHz range — think relay drivers, logic-level interface buffers, or LED indicator switching in industrial controls and consumer appliances.
Infineon lists the BCR133SE6433BTMA1 as obsolete. That means no further factory production — no last-time-buy window remains. The base product number is BCR133S, so any official replacement would share that prefix. No successor order code appears on the lifecycle record. If you need a drop-in alternative, a dual NPN pre-biased transistor in SOT-363 with matching 10kOhm / 10kOhm resistor values is the parametric match to search for — but verify the pinout against your layout before committing a board spin.
Package and storage notes
The small 6-pin footprint fits tight layouts.