onsemi BC337-40RL1

Overview

BC337-40RL1 from ON Semiconductor is an NPN silicon general-purpose amplifier transistor in TO-92 package, rated for 45 V_CEO, 800 mA continuous collector current, and DC current gain (h_FE) of 250–630 at I_C = 100 mA, V_CE = 1.0 V. It operates across −55 °C to +150 °C junction temperature and is commonly used in low-voltage switching and linear amplification stages of consumer power supplies and signal conditioning circuits.

For engineers reviewing the BC337-40RL1 datasheet, pinout, applications, or equivalent options, key selection considerations include its guaranteed minimum h_FE of 250, V_CE(sat) ≤ 0.7 V at I_C/I_B = 10, thermal resistance R_JA = 200 °C/W, and Pb-free TO-92 tape-and-reel packaging (2000 units/reel).

Technical Context

The BC337-40RL1 is a discrete bipolar junction transistor optimized for medium-current linear amplification and saturated switching. Its h_FE binning (−40 suffix) ensures minimum DC gain of 250, supporting stable biasing in emitter-follower and common-emitter configurations without external gain stabilization.

It features V_(BR)CEO = 45 V, V_CE(sat) = 0.7 V max at I_C = 500 mA/I_B = 50 mA, and f_T = 210 MHz typical - enabling use in audio-frequency amplifiers and low-speed digital interface drivers up to ~10 MHz switching.

Key Specifications

Pinout & Package

BC337-40RL1 uses the standard TO-92 (Case 29, Style 17) plastic package with 3 leads, 4.45–5.20 mm height, and 2.54 mm lead pitch. Lead finish is matte tin (Pb-free per J-STD-609).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC337-40 and BC817-40,215, the BC337-40RL1 uniquely combines tape-and-reel automation support, 800 mA current capability, and 200 °C/W thermal resistance - making it optimal for cost-sensitive, medium-power through-hole or mixed-technology designs requiring volume manufacturability.

Availability

BC337-40RL1 is available at Aetrix Electronics and suitable for LED driver circuits, relay interfaces, audio pre-amplifiers, and power supply error amplifiers requiring stable component supply and RoHS-compliant manufacturing.

Supply support for BC337-40RL1 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

ON Semiconductor (now part of onsemi) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensor, and connectivity solutions for automotive, industrial, and consumer markets.

The BC337-40RL1 belongs to the BC337 family of general-purpose NPN transistors designed for cost-effective, high-reliability linear amplification and switching in non-safety-critical commercial and industrial equipment.

FAQ

What is the guaranteed DC current gain (h_FE) range for BC337-40RL1?

The BC337-40RL1 is binned to guarantee h_FE between 250 and 630 when measured at I_C = 100 mA and V_CE = 1.0 V. This tight gain spread ensures predictable bias point stability in production amplifiers and switching circuits without requiring individual calibration or trimming. The "−40" suffix explicitly denotes this gain grade, distinguishing it from BC337-16 (h_FE = 100–250) and BC337-25 (h_FE = 160–400).

Is BC337-40RL1 compatible with lead-free reflow soldering processes?

Yes, BC337-40RL1 is manufactured with a Pb-free matte tin lead finish and qualified for standard lead-free reflow profiles (J-STD-020, peak 260 °C). Its TO-92 package withstands three reflow cycles without delamination or parametric shift. The "RL1" suffix confirms tape-and-reel packaging optimized for automated placement and RoHS compliance - verified per onsemi's Soldering and Mounting Techniques Reference Manual.

What is the maximum safe collector-emitter voltage for BC337-40RL1 in continuous operation?

The absolute maximum V_CEO rating for BC337-40RL1 is 45 VDC. Operation above this voltage risks avalanche breakdown and permanent device failure. For reliable long-term use, design margins should limit steady-state V_CE to ≤ 36 V (80 % of rating), especially in inductive load switching where transient spikes may exceed nominal rail voltage. The BC337-40RL1 datasheet specifies V_(BR)CES = 50 V only under pulsed test conditions (I_C = 100 µA), not continuous stress.

Can BC337-40RL1 replace BC337-25 in an existing design?

Yes, BC337-40RL1 can directly replace BC337-25 in most designs because both share identical package (TO-92), pinout, voltage/current ratings, and thermal characteristics. The primary difference is higher guaranteed h_FE (250–630 vs. 160–400), which may improve base drive efficiency but does not require circuit modification. Verify that increased gain does not cause unintended saturation in precision bias networks - though typical applications like LED drivers and relay interfaces benefit from the upgrade.

What is the thermal resistance from junction to ambient (R_JA) for BC337-40RL1 in free-air conditions?

The BC337-40RL1 has a specified R_JA of 200 °C/W when mounted on a standard FR-4 PCB with no copper pour or heatsink. This means a 625 mW power dissipation raises the junction temperature by 125 °C above ambient - limiting usable power to ~312 mW at 25 °C ambient to stay within the 150 °C T_J(max). For higher loads, add thermal relief pads or use the device's lower R_JC = 83.3 °C/W with a heatsink attached to the collector lead.