BC846B-QR

BC846B-QR is a RoHS-compliant, NPN small-signal transistor in the BC846 family, typically used for general-purpose amplification and switching in SOT-23 packages.
Key points:
- Type: NPN, small-signal transistor
- Package: SOT-23; -QR generally denotes RoHS lead-free packaging (check the specific supplier for exact packaging/tape code)
- Max ratings: Vceo ≈ 45 V; Ic max ≈ 100 mA
- Gain: hFE group B ≈ 200–450 (at Ic ≈ 2 mA; values vary by part and temp)
- Characteristics: relatively low noise, suitable for audio/signal conditioning and buffering
- Applications: amplification stages, switches, sensor interfacing, general purpose small-signal tasks
- How to use: bias with a base resistor to set the required base current; operate in the active region for linear amplification or saturate for switching
Availability: widely offered by major vendors (ON Semi, NXP, Renesas, etc.); verify exact specs and packaging in the datasheet for the -QR variant.

BC846B-QR is a NPN, low-noise small-signal transistor in SOT-23. Common equivalents (SMD): MMBT3904 (ON/Sem/TI/Diodes Inc), DMMT3904; BC847B (same family; pinout compatible); BC846A/BC846C or BC847A/C (gain variants). Through-hole substitute: 2N3904. Note: check Vce, Ic and pinout in datasheets for a true drop-in.

BC846B-QR is a general‑purpose NPN transistor. Key features:
- NPN transistor in SOT-23 package
- High current gain (hFE group B; roughly 200–450)
- Collector current up to 100 mA
- Collector–emitter voltage Vceo up to 45 V
- Low-noise, suitable for small‑signal amplification and switching
- Fast switching characteristics
- Pb‑free, RoHS compliant
- Tape‑and‑reel packaging (QR suffix) for automated assembly
- Complementary to BC856 (PNP)

- Pin count: 3
- Function: NPN general-purpose small-signal transistor (SOT-23 package), used for switching and amplification. Pinout (typical, BC846B in SOT-23): Pin 1 = Collector, Pin 2 = Base, Pin 3 = Emitter. The -QR suffix denotes Tape & Reel packaging.

- Manufacturer: Nexperia (formerly Philips/NXP).
- What kind of company: A global semiconductor company specializing in discrete components (transistors, diodes), logic devices, and MOSFETs, catering to high-volume, cost-optimized electronics applications.

BC846B-QR is a general-purpose NPN transistor in SMD (QR) packaging. Common application areas:
- Small-signal amplification and switching in low-power circuits
- Buffering and level-shifting between stages
- Audio preamps, sensor signal conditioning, and interface circuits
- Driver stages for other transistors or ICs in portable/consumer electronics
- General purpose replacement for BC546/BC547 in surface-mount designs
Note: typically RoHS-compliant, tape-and-reel packaging suitable for automated assembly.

BC846B-QR is in a SOT-23 (3-pin) surface-mount package. The -QR suffix typically denotes Tape & Reel packaging.