Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

onsemi BC337-40ZL1

Name: BC337-40ZL1
Brand: onsemi
SKU: BC337-40ZL1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: BC337-40ZL1

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 Long Body, Formed Leads

Datasheet:: BC337-40ZL1.pdf

Description:: TRANS NPN 45V 0.8A TO92

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:5,200

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

BC337-40ZL1 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 DC current gain (h_FE) of 250–630 at I_C = 100 mA, V_CE = 1.0 V - used in low-voltage switching and linear amplification stages of power supplies, sensor interfaces, and LED drivers.

For engineers reviewing the BC337-40ZL1 datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed h_FE ≥ 250, V_CEO = 45 V, TO-92 thermal resistance R_JA = 200 °C/W, and Pb-free Ammo Box packaging for automated assembly.

Technical Context

The BC337-40ZL1 operates as a medium-power NPN bipolar junction transistor optimized for linear amplification and saturated switching. Its h_FE binning (−40 suffix) ensures minimum DC current gain of 250 at 100 mA, with V_CE(sat) ≤ 0.7 V at I_C = 500 mA / I_B = 50 mA and f_T = 210 MHz typical for RF-capable small-signal use.

Designed for ambient-temperature operation up to +150°C junction, it features V_EBO = 5.0 V, C_ob = 15 pF at 10 V, and safe operating area limited by thermal resistance R_JC = 83.3 °C/W - enabling reliable use in thermally constrained PCB layouts without forced cooling.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	45 V - supports rail voltages up to 45 V in switching regulators and relay drivers without breakdown.
I_C (continuous)	800 mA - delivers sufficient drive current for medium-power loads like solenoids and fan motors.
h_FE (min)	250 @ I_C = 100 mA - ensures stable biasing and predictable gain in amplifier stages without external feedback trimming.
V_CE(sat)	≤ 0.7 V @ I_C/I_B = 10 - minimizes conduction loss and self-heating in saturated-switch applications.
f_T	210 MHz typical - enables use in audio preamps and low-frequency RF signal conditioning up to ~100 MHz.
R_JA	200 °C/W - defines maximum power dissipation (625 mW @ T_A = 25°C) under natural convection cooling.

Pinout & Package

BC337-40ZL1 uses TO-92 package (Case 29, Style 17), with standardized lead configuration: Pin 1 = Collector, Pin 2 = Base, Pin 3 = Emitter. Package dimensions comply with ANSI Y14.5M and support through-hole mounting and wave soldering.

Pin/Terminal	Circuit Role	Design Meaning
1 (Collector)	Main current output terminal	Connected to load or supply rail; carries full switched/signal current; requires thermal consideration due to power dissipation path.
2 (Base)	Control input node	Receives bias current to regulate collector-emitter conduction; high-impedance input requiring current-limited drive.
3 (Emitter)	Current return path	Typically grounded or connected to emitter resistor for stabilization; sets reference for V_BE and gain control.

Key Features

Feature	Design Value
Guaranteed h_FE bin (−40)	Min 250 at 100 mA - eliminates need for gain screening in production assemblies.
Pb-free Ammo Box packaging (ZL1)	2000 units per ammo box - optimized for high-speed pick-and-place placement with consistent orientation and traceability.
V_EBO = 5.0 V	Enables direct interface with 3.3 V/5 V logic outputs without level-shifting components.
TO-92 thermal performance	R_JA = 200 °C/W and R_JC = 83.3 °C/W - supports 625 mW dissipation at room ambient and efficient heat transfer to PCB copper.

Applications

DC Power Switching	Audio Signal Amplification
Use Scenario: Low-side switching of 12 V DC loads such as relays, LEDs, and small solenoids in industrial control panels. IC Role / Device Role / Timing Role: NPN switch operating in saturation mode with base-driven current control. Use Value: V_CE(sat) ≤ 0.7 V ensures <100 mW conduction loss at 500 mA, reducing thermal stress on PCB.	Use Scenario: Pre-amplifier stage in battery-powered audio mixers and microphone input circuits. IC Role / Device Role / Timing Role: Linear Class-A amplifier with fixed emitter degeneration for low-noise voltage gain. Use Value: h_FE ≥ 250 and f_T = 210 MHz enable stable 20–20 kHz gain flatness without oscillation risk.
Sensor Interface Buffer	Microcontroller GPIO Driver
Use Scenario: Isolating and amplifying analog output from temperature or pressure sensors before ADC sampling. IC Role / Device Role / Timing Role: Emitter-follower buffer providing low-output-impedance drive to ADC input. Use Value: V_EBO = 5.0 V allows direct connection to 3.3 V microcontroller ADC references without clamping diodes.	Use Scenario: Driving higher-current peripherals (e.g., optocouplers, small MOSFET gates) from MCU GPIO pins. IC Role / Device Role / Timing Role: Digital switch translating 3.3 V/5 V logic levels to 45 V capable output. Use Value: 45 V_CEO rating permits safe interfacing with off-board 24 V industrial I/O while protecting MCU pins.

DC Power Switching

Audio Signal Amplification

Use Scenario: Low-side switching of 12 V DC loads such as relays, LEDs, and small solenoids in industrial control panels.

IC Role / Device Role / Timing Role: NPN switch operating in saturation mode with base-driven current control.

Use Value: V_CE(sat) ≤ 0.7 V ensures <100 mW conduction loss at 500 mA, reducing thermal stress on PCB.

Use Scenario: Pre-amplifier stage in battery-powered audio mixers and microphone input circuits.

IC Role / Device Role / Timing Role: Linear Class-A amplifier with fixed emitter degeneration for low-noise voltage gain.

Use Value: h_FE ≥ 250 and f_T = 210 MHz enable stable 20–20 kHz gain flatness without oscillation risk.

Sensor Interface Buffer

Microcontroller GPIO Driver

Use Scenario: Isolating and amplifying analog output from temperature or pressure sensors before ADC sampling.

IC Role / Device Role / Timing Role: Emitter-follower buffer providing low-output-impedance drive to ADC input.

Use Value: V_EBO = 5.0 V allows direct connection to 3.3 V microcontroller ADC references without clamping diodes.

Use Scenario: Driving higher-current peripherals (e.g., optocouplers, small MOSFET gates) from MCU GPIO pins.

IC Role / Device Role / Timing Role: Digital switch translating 3.3 V/5 V logic levels to 45 V capable output.

Use Value: 45 V_CEO rating permits safe interfacing with off-board 24 V industrial I/O while protecting MCU pins.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC337-40RL1	Same electrical specs; tape-and-reel packaging (2000 pcs) instead of ammo box.	Optimized for SMT reflow lines using pick-and-place feeders rather than manual or bulk-feed assembly.	Select when integrating into automated surface-mount production with reel-based feeding systems.
BC337-40G	Identical electrical parameters; Pb-free TO-92 in bulk box (5000 pcs), no ammo packaging.	Suitable for hand-soldering, prototyping, or low-volume through-hole assembly where orientation control is not required.	Choose for lab evaluation, repair, or small-batch manufacturing without ammo-box handling infrastructure.

Compared with BC337-40ZL1, BC337-40RL1 offers identical performance in tape-and-reel format for SMT lines, while BC337-40G provides same-spec bulk delivery for manual assembly - all three share h_FE ≥ 250, V_CEO = 45 V, and TO-92 thermal behavior, differing only in packaging method and quantity unit.

Availability

BC337-40ZL1 is available at Aetrix Electronics and suitable for industrial control systems, sensor signal conditioning, and low-voltage power switching applications requiring stable component supply and Pb-free compliance.

Supply support for BC337-40ZL1 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, and consumer markets.

The BC337 series belongs to onsemi's legacy general-purpose bipolar transistor product line, designed specifically for cost-sensitive, high-reliability linear amplification and switching in industrial and consumer equipment.

FAQ

What is the guaranteed DC current gain (h_FE) range for BC337-40ZL1?

The BC337-40ZL1 is binned to guarantee h_FE ≥ 250 at I_C = 100 mA and V_CE = 1.0 V, with typical values reaching 630 under those conditions. This binning ensures predictable biasing in amplifier and switching designs without gain variation-related recalibration. The −40 suffix explicitly denotes this minimum gain specification for BC337-40ZL1.

Is BC337-40ZL1 RoHS-compliant and Pb-free?

Yes, BC337-40ZL1 is Pb-free and RoHS-compliant, as confirmed by onsemi's official documentation and marking designation "ZL1G" variant (though ZL1 itself is Pb-free per onsemi's Pb-Free Strategy referenced in the datasheet). The device meets JEDEC J-STD-609 Category 1 requirements and supports lead-free soldering processes up to 260°C peak temperature.

What is the maximum power dissipation for BC337-40ZL1 at 25°C ambient?

BC337-40ZL1 has a total device dissipation (P_D) of 625 mW at T_A = 25°C, derating linearly by 5.0 mW/°C above that temperature. This value assumes standard TO-92 mounting on FR-4 PCB with minimal copper; actual dissipation may increase with added copper pour or heatsinking, but R_JA = 200 °C/W remains the baseline thermal limit for BC337-40ZL1.

Can BC337-40ZL1 replace BC337-25ZL1 in an existing design?

Yes, BC337-40ZL1 can directly replace BC337-25ZL1 because both share identical package (TO-92), pinout, voltage/current ratings, and thermal characteristics - the only difference is guaranteed h_FE (250–630 vs. 160–400). Higher gain improves noise immunity and reduces base drive requirements, making BC337-40ZL1 a functional upgrade without layout changes.

What is the safe operating area (SOA) limitation for BC337-40ZL1 in pulsed operation?

Per Figure 2 in the onsemi datasheet, BC337-40ZL1's SOA is bounded by thermal limits at DC and long pulses (>1 s), current limiting at short pulses (<1 ms), and second breakdown at intermediate durations. At 10 ms pulse width, max I_C is ~300 mA at V_CE = 30 V - critical for designing flyback snubbers or motor commutation circuits where BC337-40ZL1 handles transient energy.

BC337-40ZL1 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 Long Body, Formed Leads

Packaging:: Tape & Box (TB)

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 800 mA

Voltage - Collector Emitter Breakdown (Max):: 45 V

Vce Saturation (Max) @ Ib, Ic:: 700mV @ 50mA, 500mA

Current - Collector Cutoff (Max):: 100nA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 250 @ 100mA, 1V

Power - Max:: 625 mW

Frequency - Transition:: 210MHz

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92 (TO-226)

BC337-40ZL1 FAQ

1.How can I place an order for BC337-40ZL1 through Aetrix?

Please submit a Request for Quotation (RFQ) for BC337-40ZL1 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for BC337-40ZL1 reliable?

The price and inventory of BC337-40ZL1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC337-40ZL1 is usually 5 days.

3.What payment methods are accepted for BC337-40ZL1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC337-40ZL1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC337-40ZL1?

BC337-40ZL1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC337-40ZL1 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for BC337-40ZL1?

For technical support, including BC337-40ZL1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC337-40ZL1 requirements.

6.How does Aetrix verify that BC337-40ZL1 is sourced from the original manufacturer or authorized distributors?

All BC337-40ZL1 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that BC337-40ZL1 meets industry standards.

7.What is the process for return or replacement of BC337-40ZL1?

All BC337-40ZL1 units undergo pre-shipment inspection (PSI). If there is an issue with BC337-40ZL1, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The BC337-40ZL1 part is unused and in its original packaging.

Return procedure for BC337-40ZL1:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

Tech Hub

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…