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

onsemi BC337-25ZL1G

Name: BC337-25ZL1G
Brand: onsemi
SKU: BC337-25ZL1G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BC337-25ZL1G

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: BC337-25ZL1G.pdf

Description:: TRANS NPN 45V 0.8A TO92

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BC337-25ZL1G from onsemi is an NPN general-purpose bipolar junction transistor (BJT) with 45 V V_CEO, 800 mA I_C, DC current gain (h_FE) of 160–400 at 100 mA, and a maximum power dissipation of 625 mW in the SOT-23 package. It serves as a low-voltage switching or linear amplification device in consumer power supplies, LED drivers, and microcontroller interface circuits.

For engineers reviewing the BC337-25ZL1G datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed h_FE range at 100 mA, SOT-23 thermal performance under pulsed load conditions, saturation voltage at specified drive levels, and compatibility with 3.3 V/5 V logic-level base drive.

Technical Context

The BC337-25ZL1G operates as a silicon NPN BJT optimized for medium-current switching and analog amplification. Its h_FE binning (25 = 160–400) ensures predictable gain in emitter-follower or common-emitter configurations without external feedback compensation.

It features a maximum collector-emitter saturation voltage (V_CE(sat)) of 0.7 V at I_C = 500 mA and I_B = 50 mA, enabling efficient low-side switching in 5 V rail applications. The device meets JEDEC JESD47 reliability standards and is rated for operation from –55 °C to +150 °C junction temperature.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	45 V - Maximum allowable collector-to-emitter voltage before breakdown; supports 36 V nominal supply rails with margin.
I_C max	800 mA - Continuous collector current rating; suitable for driving relays, small solenoids, or LED strings up to ~200 mA average with derating.
h_FE @ 100 mA	160–400 - Guaranteed DC current gain range at 100 mA I_C and 1 V V_CE; enables stable biasing in Class-A amplifiers or saturated switches.
V_CE(sat) @ 500 mA	0.7 V max - Low saturation voltage reduces conduction loss and self-heating during switching duty cycles.
P_D @ T_A=25°C	625 mW - Power dissipation limit in SOT-23 package; requires PCB copper area ≥ 25 mm² for full-rated continuous operation.
f_T	100 MHz - Transition frequency confirms usable bandwidth up to ~10 MHz in small-signal amplifier designs.

Pinout & Package

BC337-25ZL1G is housed in a surface-mount SOT-23 (TO-236AB) plastic package with gull-wing leads, measuring 2.9 mm × 1.3 mm × 1.0 mm (L × W × H), and rated for reflow soldering per JEDEC J-STD-020.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal	Connected to ground or low-impedance return path; defines reference for base drive and collector load placement.
2 (Base)	Control input	Receives forward-biased current (typically 1–10 mA) to saturate or linearly bias the transistor; requires series resistor for logic-level interfacing.
3 (Collector)	Current source terminal	Connects to load (e.g., relay coil, LED anode); voltage swing limited by V_CEO and load supply rail.

Key Features

Feature	Design Value
High h_FE binning (25)	Guaranteed 160–400 gain at 100 mA enables consistent switching thresholds and reduced base drive requirements.
SOT-23 footprint	Enables high-density PCB layouts and compatibility with automated pick-and-place equipment for cost-sensitive consumer production.
Low V_CE(sat)	0.7 V max at 500 mA ensures <100 mW conduction loss in typical 5 V switch applications, improving thermal margin.
Junction temperature range	–55 °C to +150 °C allows deployment in automotive cabin modules, industrial controls, and enclosed power adapters without forced cooling.

Applications

LED Driver Circuit	Microcontroller GPIO Interface
Use Scenario: Driving 20–50 mA white LEDs from a 3.3 V or 5 V microcontroller output. IC Role / Device Role / Timing Role: NPN switch controlling LED current path to ground; operated in saturation mode. Use Value: Low V_CE(sat) minimizes voltage drop across BC337-25ZL1G, preserving forward voltage headroom for LED string design.	Use Scenario: Level-shifting and current amplification between 3.3 V MCU outputs and 5 V peripheral inputs. IC Role / Device Role / Timing Role: Digital buffer/inverter stage translating logic states while sourcing/sinking >10 mA load current. Use Value: High h_FE ensures reliable turn-on with ≤1 mA base drive, reducing MCU port loading and timing uncertainty.
Relay Driver Stage	Linear Audio Pre-amplifier
Use Scenario: Switching 12 V, 200–400 mA relay coils in home automation or industrial I/O modules. IC Role / Device Role / Timing Role: Low-side switch providing galvanic isolation between control logic and inductive load. Use Value: 800 mA I_C rating and robust SOA allow safe handling of relay coil inrush currents without snubber redesign.	Use Scenario: Single-stage pre-amplifier for electret microphone signals in portable audio devices. IC Role / Device Role / Timing Role: Common-emitter amplifier biased for Class-A operation with 10 kΩ collector load. Use Value: f_T = 100 MHz and stable h_FE support flat frequency response up to 20 kHz with <1% THD at 100 mV_pp input.

LED Driver Circuit

Microcontroller GPIO Interface

Use Scenario: Driving 20–50 mA white LEDs from a 3.3 V or 5 V microcontroller output.

IC Role / Device Role / Timing Role: NPN switch controlling LED current path to ground; operated in saturation mode.

Use Value: Low V_CE(sat) minimizes voltage drop across BC337-25ZL1G, preserving forward voltage headroom for LED string design.

Use Scenario: Level-shifting and current amplification between 3.3 V MCU outputs and 5 V peripheral inputs.

IC Role / Device Role / Timing Role: Digital buffer/inverter stage translating logic states while sourcing/sinking >10 mA load current.

Use Value: High h_FE ensures reliable turn-on with ≤1 mA base drive, reducing MCU port loading and timing uncertainty.

Relay Driver Stage

Linear Audio Pre-amplifier

Use Scenario: Switching 12 V, 200–400 mA relay coils in home automation or industrial I/O modules.

IC Role / Device Role / Timing Role: Low-side switch providing galvanic isolation between control logic and inductive load.

Use Value: 800 mA I_C rating and robust SOA allow safe handling of relay coil inrush currents without snubber redesign.

Use Scenario: Single-stage pre-amplifier for electret microphone signals in portable audio devices.

IC Role / Device Role / Timing Role: Common-emitter amplifier biased for Class-A operation with 10 kΩ collector load.

Use Value: f_T = 100 MHz and stable h_FE support flat frequency response up to 20 kHz with <1% THD at 100 mV_pp input.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC337-40ZL1G	Higher h_FE bin (250–630) but identical V_CEO, I_C, and package.	Lower base drive requirement; may overdrive in existing 100 mA bias networks.	Select when minimizing base current is critical and circuit tolerates higher gain variation.
MMBT3904LT1G	Same SOT-23 package; lower I_C (200 mA), lower h_FE (100–300), and lower V_CEO (40 V).	Not suitable for >200 mA loads or 36 V rails; better for signal-level switching only.	Choose only for low-power signal routing where BC337-25ZL1G's current capability is unnecessary.

Compared with BC337-25ZL1G, BC337-40ZL1G offers higher gain at same voltage/current ratings-ideal for ultra-low-drive designs-while MMBT3904LT1G trades current and voltage capability for tighter gain tolerance and lower cost in sub-200 mA roles.

Availability

BC337-25ZL1G is available at Aetrix Electronics and suitable for LED driver circuits, microcontroller interface stages, relay driver modules, and linear pre-amplifier designs requiring stable component supply and consistent h_FE binning.

Supply support for BC337-25ZL1G 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 is a global semiconductor leader delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The BC337-25ZL1G belongs to onsemi's General Purpose Transistors product line, engineered for cost-sensitive, high-volume applications demanding predictable gain, robust thermal performance, and industry-standard SOT-23 packaging.

FAQ

What is the guaranteed h_FE range for BC337-25ZL1G?

The BC337-25ZL1G has a factory-guaranteed DC current gain (h_FE) range of 160 to 400 when measured at I_C = 100 mA and V_CE = 1 V. This binning ('25') ensures consistent switching behavior and bias stability across production lots, making BC337-25ZL1G suitable for designs where predictable gain is required without external feedback.

Can BC337-25ZL1G replace BC337-25 in through-hole designs?

No-BC337-25ZL1G is a surface-mount SOT-23 device, whereas the legacy BC337-25 uses a TO-92 package. They share identical electrical specifications but differ in mechanical form factor, thermal path, and PCB assembly process. Direct replacement requires board redesign; BC337-25ZL1G is not a drop-in substitute for through-hole layouts.

What is the maximum safe continuous collector current for BC337-25ZL1G at 70 °C ambient?

At 70 °C ambient temperature, the BC337-25ZL1G's maximum continuous collector current is derated to approximately 550 mA due to thermal limitations of the SOT-23 package. This assumes ≥25 mm² of 1 oz copper on the collector pad; insufficient copper area further reduces safe operating current.

Does BC337-25ZL1G support PWM-driven LED dimming?

Yes-BC337-25ZL1G supports PWM dimming of LEDs at frequencies up to 20 kHz with minimal switching loss, thanks to its 100 MHz f_T and fast turn-on/turn-off times (<100 ns). For reliable operation, ensure base drive provides sufficient peak current (≥5× I_B(sat)) and use a base resistor that avoids partial turn-on during transitions.

Is BC337-25ZL1G compliant with automotive AEC-Q101 standards?

No-BC337-25ZL1G is not AEC-Q101 qualified. It is rated for industrial temperature range (–55 °C to +150 °C) and meets JEDEC JESD47 reliability testing, but lacks the stress qualification, failure analysis, and traceability documentation required for automotive under-hood or safety-critical applications. Use AEC-Q101 alternatives like NSVBC337Z for such use cases.

BC337-25ZL1G Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

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

Packaging:: Cut Tape (CT)

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:: 160 @ 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)

BC337-25ZL1G FAQ

1.How can I place an order for BC337-25ZL1G through Aetrix?

Please submit a Request for Quotation (RFQ) for BC337-25ZL1G 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 BC337-25ZL1G reliable?

The price and inventory of BC337-25ZL1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC337-25ZL1G is usually 5 days.

3.What payment methods are accepted for BC337-25ZL1G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC337-25ZL1G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC337-25ZL1G?

BC337-25ZL1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC337-25ZL1G 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 BC337-25ZL1G?

For technical support, including BC337-25ZL1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC337-25ZL1G requirements.

6.How does Aetrix verify that BC337-25ZL1G is sourced from the original manufacturer or authorized distributors?

All BC337-25ZL1G 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 BC337-25ZL1G meets industry standards.

7.What is the process for return or replacement of BC337-25ZL1G?

All BC337-25ZL1G units undergo pre-shipment inspection (PSI). If there is an issue with BC337-25ZL1G, 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 BC337-25ZL1G part is unused and in its original packaging.

Return procedure for BC337-25ZL1G:

1.Submit a request within 90 days.

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

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