BC817-25QAZ

BC817-25QAZ is a general-purpose NPN small-signal transistor in an SOT-23 package (surface-mount). It’s used for switching and amplification in low-power circuits.
Key points:
- Type: NPN transistor, BC817 family
- Package: SOT-23, RoHS-compliant
- Vceo: ~45 V
- Ic: up to ~500 mA
- Hfe: around 100–250 for the -25 group (actual value varies by device)
- Temp range: roughly -55°C to +150°C
- Marking/code: QAZ (manufacturer/date code)
- Applications: signal amplification, switching, drivers in consumer electronics
Note: Exact electrical parameters vary by lot and variant. Always consult the latest datasheet (from Nexperia/Diodes Inc or the vendor) for precise hFE, Vceo, current limits, and safe operating area before design or procurement.

Common equivalents to a BC817-25 (general-purpose NPN) are other BC817-25 variants from different manufacturers plus similar NPNs such as BC337-25, 2N2222 / PN2222A (through-hole) and MMBT2222 / 2N3904 (SMD). Always verify Vce, Ic, hFE, package and pinout before substituting.

Here are the core features of BC817-25QAZ:
- NPN general‑purpose transistor
- Package: TO‑92 through‑hole, Pb‑free, RoHS compliant (suffix QAZ)
- Vceo: 45 V maximum
- Ic: up to 500 mA
- DC current gain (hFE): wide range, typical 110–800 (depends on Ic and temperature; grade varies by lot)
- Low saturation voltage when used as a switch (Vce(sat) ≈ 0.2–0.3 V under proper drive)
- Complementary to BC807 (PNP)
- Operating temp: typically −55°C to +150°C
- Applications: general amplification and switching in low‑power circuits (drivers, regulators, audio, small signal amplification)
Note: exact hFE and Vce(sat) depend on operating conditions and device lot.

Pin count: 3 (SOT‑23 package).
Function: NPN bipolar transistor — the three pins are Base (B), Collector (C) and Emitter (E). Exact pin numbering/orientation (which pad is B, C or E) is package‑view dependent, so consult the BC817‑25QAZ manufacturer datasheet or product marking for the definitive pin assignment.

Manufacturer: Diodes Incorporated.
Company type: Diodes Inc. is a global semiconductor manufacturer and supplier that designs and manufactures discrete semiconductors, logic and analog integrated circuits (diodes, transistors, MOSFETs, power-management devices) for industrial, computing, automotive and consumer markets.

BC817-25QAZ is a general‑purpose NPN small‑signal transistor (SOT‑23). Typical applications:
- Switching and amplification in low‑power circuits (Vce ≈ 45 V, Ic up to ~500 mA)
- Driving loads like LEDs, relays, and optocouplers
- Buffering and level‑shifting interfaces for microcontrollers and logic
- Small‑signal preamplifiers and sensor front‑end stages
- Biasing networks and general signal conditioning in consumer electronics

SOT-23 (3-pin) surface-mount package.