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. For a BOM line that calls out this exact order code, the supply channel shifts to independent distribution: new-old-stock or surplus inventory already in the field. 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
Supplied in Tape & Reel (TR) format, surface-mount in a 6-VSSOP / SC-88 / SOT-363 package, with the Infineon-specific PG-SOT363-PO supplier designation. The small 6-pin footprint fits tight layouts. Store the reels dry — these small SOT packages are moisture-sensitive, and a bake cycle before reflow adds cost if the moisture-barrier bag has been open past the floor-life window.