Nexperia USA Inc. BC817,235

Overview

BC817,235 from Nexperia is an NPN general-purpose bipolar junction transistor in SOT23 (TO-236AB) package, rated for 45 V V_CEO, 500 mA continuous collector current, and DC current gain (h_FE) of 100–600 at I_C = 100 mA. It serves as a low-voltage switching and linear amplification device in consumer power management, signal buffering, and discrete logic interface circuits.

For engineers reviewing the BC817,235 datasheet, BC817,235 pinout, BC817,235 application, or BC817,235 equivalent, key selection criteria include its 45 V breakdown voltage, thermal resistance of 500 K/W on standard FR4 PCB, SOT23 footprint compatibility, and three h_FE variants optimized for gain-stability trade-offs in bias-sensitive designs.

Technical Context

The BC817,235 operates as a silicon planar epitaxial NPN transistor with base-emitter and collector-base junctions designed for stable DC amplification and fast-switching duty cycles up to 1 ms. Its pulsed peak collector current reaches 1 A, and saturation voltage remains ≤700 mV at I_C = 500 mA / I_B = 50 mA.

Thermal performance is defined for two mounting conditions: 500 K/W junction-to-ambient on standard footprint and 362 K/W with 1 cm² collector pad. Transition frequency f_T is 100 MHz at V_CE = 5 V, I_C = 10 mA, enabling use in low-frequency RF coupling and audio preamplifier stages.

Key Specifications

Pinout & Package

SOT23 (TO-236AB) plastic surface-mounted package with 3 leads; 1.3 mm × 2.9 mm footprint, 1.1 mm height, and tin-plated copper leads compatible with reflow and wave soldering per IPC-J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC817,235, BC847B,235 trades current capacity for tighter gain control in low-power analog paths, while MMBT3904LT1G offers wider distributor stock at the cost of 5 V lower breakdown margin and reduced thermal robustness on standard PCBs.

Availability

BC817,235 is available at Aetrix Electronics and suitable for LED driver circuits, microcontroller GPIO expansion, and DC motor on/off control requiring stable component supply, consistent h_FE binning, and SOT23 footprint compatibility.

Supply support for BC817,235 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 and industrial-grade components.

The BC817 series belongs to Nexperia's general-purpose transistor product line, engineered for cost-effective, robust switching and amplification in consumer, industrial, and computing applications where reliability and manufacturability are prioritized.

FAQ

What is the maximum allowable junction temperature for BC817,235?

The absolute maximum junction temperature (T_j) is 150 °C, as specified in Table 6 of the datasheet. Operation above this limit risks permanent parametric shift or failure. Derating begins at 25 °C ambient, with total power dissipation dropping linearly to zero at 150 °C junction temperature.

Does BC817,235 require a base resistor in switching applications?

Yes - a series base resistor is mandatory to limit I_B and prevent excessive base current. For 500 mA collector current with h_FE = 100, minimum I_B = 5 mA; typical design uses I_B = 10 mA (2× saturation margin), requiring ~330 Ω from 3.3 V GPIO after accounting for V_BE ≈ 1.2 V.

How does BC817,235 compare to BC817-16 in terms of h_FE range?

BC817,235 is the base part number without h_FE binning; its datasheet specifies h_FE = 100–600. BC817-16 is a factory-binned variant with guaranteed h_FE = 100–250. The "235" suffix refers to packaging and reel specification, not gain grading - actual h_FE must be verified per unit or selected as -16/-25/-40 for design certainty.

Can BC817,235 be used in linear regulator pass transistor roles?

No - it lacks the Safe Operating Area (SOA) characterization and thermal stability required for linear regulation. Its maximum continuous power dissipation is 250 mW at 25 °C ambient (derated to zero at 150 °C), insufficient for sustained pass-transistor duty. Use dedicated LDOs or power transistors with SOA graphs instead.