onsemi BC337RL1

Overview

BC337RL1 from onsemi is an NPN silicon general-purpose amplifier transistor in TO-92 package, rated for 45 V_CEO, 800 mA continuous collector current, and 625 mW power dissipation at 25°C ambient. It delivers DC current gain (h_FE) of 100–630 depending on bias, with f_T = 210 MHz and V_CE(sat) ≤ 0.7 V at I_C = 500 mA / I_B = 50 mA - used in low-voltage switching and linear amplification stages of consumer power supplies and signal conditioning circuits.

For engineers reviewing the BC337RL1 datasheet, pinout, applications, or equivalent options, key selection criteria include V_CEO/I_C derating above 25°C, thermal resistance R_JA = 200°C/W, safe operating area (SOA) limits, h_FE binning (standard BC337 vs. −16/−25/−40 variants), and Pb-free tape-and-reel packaging compliance.

Technical Context

The BC337RL1 operates as a discrete bipolar junction transistor with fixed NPN polarity and single-die construction. Its electrical behavior is defined by three-terminal DC parameters (V_CEO, h_FE, V_BE(on), V_CE(sat)) and small-signal characteristics (f_T = 210 MHz, C_ob = 15 pF), all specified at T_A = 25°C with defined test conditions (e.g., I_C = 100 mA, V_CE = 1.0 V for h_FE).

Thermal performance is governed by R_JA = 200°C/W (junction-to-ambient) and R_JC = 83.3°C/W (junction-to-case), enabling operation from −55°C to +150°C junction temperature. Safe operating area (SOA) is bounded by second breakdown, thermal limit, and current limit curves - critical for pulsed switching applications where duty cycle and peak power must remain within Figure 2 boundaries.

Key Specifications

Pinout & Package

BC337RL1 uses the TO-92 (Case 29, Style 17) through-hole plastic package with 3 leads. Pin 1 is Collector, Pin 2 is Base, Pin 3 is Emitter - confirmed by marking diagram and package outline on page 4 of BC337/D Rev. 5.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC337-25RL1, the BC337RL1 offers lower guaranteed h_FE but identical voltage/current ratings and thermal capability - making it preferable for cost-sensitive, gain-tolerant switching. Versus BC817-40LT1G, BC337RL1 provides 60% higher I_C rating and 33% better R_JA, supporting higher-power through-hole implementations without thermal compromise.

Availability

BC337RL1 is available at Aetrix Electronics and suitable for LED driver circuits, DC motor control stages, audio pre-amplifier stages, and power supply feedback transistors requiring stable component supply, consistent TO-92 lead form, and RoHS-compliant tape-and-reel packaging.

Supply support for BC337RL1 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

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

The BC337RL1 belongs to onsemi's legacy general-purpose bipolar transistor product line, designed for cost-effective, reliable amplification and switching in non-safety-critical industrial and consumer electronics where proven TO-92 reliability and broad parameter tolerance are prioritized.

FAQ

What is the maximum collector current rating for BC337RL1 at 25°C ambient?

The BC337RL1 is rated for 800 mA continuous collector current (I_C) at T_A = 25°C. This rating assumes free-air convection cooling and derates linearly at 5.0 mW/°C above 25°C ambient, meaning usable current drops to approximately 500 mA at 85°C ambient. The BC337RL1 must be operated within its Safe Operating Area (SOA) curve - especially under pulsed conditions - to avoid second breakdown.

Does BC337RL1 have a Pb-free version, and how is it marked?

Yes, the Pb-free version is designated BC337RL1G and carries the same TO-92 package and electrical specifications as BC337RL1. It is marked identically with "7" on the package body and complies with RoHS Directive 2011/65/EU. Both BC337RL1 and BC337RL1G are supplied in tape-and-reel format (2000 units per reel), with the 'G' suffix indicating lead-free termination per JESD97 standards.

What is the DC current gain (h_FE) range for BC337RL1, and how does it differ from BC337-25RL1?

The BC337RL1 is the standard-gain variant with h_FE ranging from 100 to 630 at I_C = 100 mA and V_CE = 1.0 V. In contrast, BC337-25RL1 is a binned version guaranteeing minimum h_FE = 250 under identical test conditions. Both share identical V_CEO, I_C, and package - the difference lies solely in h_FE distribution, selected during final test screening.

Can BC337RL1 be used in switching applications, and what is its typical V_CE(sat)?

Yes, BC337RL1 is widely used in low-frequency switching applications such as relay drivers and LED controls. Its typical V_CE(sat) is ≤ 0.7 V at I_C = 500 mA and I_B = 50 mA (I_C/I_B = 10), ensuring low conduction loss. For reliable saturation, base drive must provide sufficient I_B; for example, driving 500 mA load requires ≥50 mA base current, achievable via appropriate series resistor from a 3.3 V or 5 V logic source.

What is the thermal resistance (R_JA) of BC337RL1, and how does it affect PCB layout?

The BC337RL1 has R_JA = 200°C/W in free-air conditions. This means a 625 mW dissipation at 25°C ambient raises junction temperature by 125°C - approaching its 150°C absolute maximum. To maintain reliability, PCB layout must minimize thermal resistance: use wide copper pours connected to emitter/collector pads, avoid enclosing the TO-92 in sealed enclosures, and consider forced airflow or heatsinking for sustained >300 mA operation.