What this PNP pre-biased transistor does
The Infineon BCR 183T E6327 is a PNP pre-biased transistor in a SC-75 (SOT-416) surface-mount package. It integrates two 10 kOhm resistors — one in series with the base (R1) and one from base to emitter (R2) — eliminating the need for external bias components in switching and driver circuits. The collector-emitter breakdown voltage is rated at 50 V, with a maximum collector current of 100 mA and a power dissipation of 250 mW. Its 200 MHz transition frequency supports moderate-speed switching applications.
Sourcing this obsolete part
Infineon has classified the BCR 183T as obsolete.
The two integrated 10 kOhm resistors set a fixed base current division ratio, simplifying the drive circuit but also fixing the turn-on threshold. With a minimum DC current gain (hFE) of 30 at 5 mA collector current and 5 V Vce, the transistor provides sufficient drive for loads up to 100 mA. The Vce saturation voltage is specified at 300 mV max with a 500 µA base current driving 10 mA collector current, giving a predictable on-state voltage drop for low-side switching. The 200 MHz transition frequency indicates it can handle switching speeds well above audio and typical power-management frequencies, though the pre-biased nature limits the designer's ability to optimize switching edges independently.
