Infineon Technologies BC 850C B5003

Overview

BC850C from Nexperia is an NPN silicon general-purpose bipolar junction transistor (BJT) designed for audio-frequency input stages and driver applications. It delivers high DC current gain (h_FE = 420–520 at I_C = 2 mA), low V_CE(sat) (max 250 mV at I_C = 10 mA / I_B = 0.5 mA), and low noise (F = 1.2–4 dB, V_n = 0.135 µV in 10–50 Hz band), enabling high-fidelity signal amplification in compact analog circuits.

For engineers reviewing the BC850C datasheet, BC850C pinout, BC850C application, or BC850C equivalent, key selection criteria include its AEC-Q101 qualification for automotive-grade reliability, SOT23 package compatibility with high-density PCB layouts, and verified performance in low-noise preamplifier and switching driver roles across temperature ranges up to 150 °C.

Technical Context

This NPN BJT operates in linear and saturated modes with V_CEO = 30 V, I_C = 100 mA continuous, and P_tot = 250 mW at T_S ≤ 124 °C. Its f_T = 250 MHz supports stable gain up to mid-VHF, while C_cb = 0.95 pF and C_eb = 9 pF ensure minimal Miller effect in amplifier feedback paths.

The device features h_FE group C grading (min 420 at I_C = 2 mA), V_BE(on) = 660–770 mV, and V_CE(sat) ≤ 250 mV - parameters optimized for low-voltage biasing and efficient switching in 3.3 V/5 V systems without external gain stabilization.

Key Specifications

Pinout & Package

BC850C is housed in a RoHS-compliant SOT23 plastic surface-mount package with standard lead frame geometry and 1.3 mm pitch. Thermal resistance R_thJS ≤ 105 K/W enables operation at T_J = 150 °C with board-level copper pour.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN general-purpose transistor applications.

Compared with BC847C and MMBT3904, BC850C provides superior noise performance and higher f_T in an AEC-Q101-qualified part, making it optimal for automotive audio front-ends and precision sensor interfaces where signal integrity and reliability are prioritized over raw cost reduction.

Availability

BC850C is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial sensor signal conditioning, and consumer audio equipment requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for BC850C includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Nexperia is a global semiconductor expert focused on high-volume, high-reliability discrete and logic devices, with leadership in automotive-qualified components and energy-efficient solutions.

BC850C belongs to Nexperia's BC846–BC850 family of AEC-Q101-qualified general-purpose transistors engineered specifically for automotive and industrial signal amplification and switching where low noise, consistent gain, and thermal robustness are essential.

FAQ

Is BC850C suitable for linear amplifier applications?

Yes - BC850C is characterized for low-noise linear operation with F = 1.2–4 dB and V_n = 0.135 µV in the 10–50 Hz band. Its h_FE group C grading ensures predictable gain linearity from 100 µA to 50 mA, validated in common-emitter and emitter-follower topologies per JEDEC JESD22-A108.

What is the maximum operating temperature for BC850C in SOT23 package?

The BC850C has a maximum junction temperature (T_j) of 150 °C and a thermal resistance R_thJS ≤ 105 K/W. When mounted on a standard 1 oz. copper PCB with 100 mm² thermal pad, it sustains 100 mA continuous current up to 85 °C ambient; derating is required above that per the P_tot vs T_S curve in Figure 8 of the datasheet.

Does BC850C support Pb-free reflow soldering?

Yes - BC850C is RoHS-compliant and qualified for lead-free reflow per JEDEC J-STD-020 Rev E. Its SOT23 package withstands peak temperatures up to 260 °C for 30 seconds, with moisture sensitivity level (MSL) 1, eliminating bake requirements prior to assembly.

How does BC850C differ from BC849C in practical design?

BC850C shares identical V_CEO, h_FE, and package with BC849C but adds specified equivalent noise voltage (V_n = 0.135 µV) and tighter noise figure (1.2–4 dB), making it preferred for microphone preamps and precision analog sensing. BC849C lacks published noise data and is typically used in non-critical switching roles.