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

onsemi BC33725TF

Name: BC33725TF
Brand: onsemi
SKU: BC33725TF
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BC33725TF

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Datasheet:: BC33725TF.pdf

Description:: TRANS NPN 45V 0.8A TO-92-3

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Product details

Overview

BC33725TF from ON Semiconductor is an NPN epitaxial silicon transistor in TO-92 package, rated for 45 V V_CEO, 800 mA I_C, and 625 mW power dissipation, with h_FE range 160–400 at I_C = 100 mA, used in low-power switching and audio driver stages.

For engineers reviewing the BC33725TF datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, TO-92 terminal mapping, real-world use cases in signal amplification and digital logic interfacing, and two validated alternative transistors with documented h_FE and voltage differences.

Technical Context

This device operates as a general-purpose bipolar junction transistor with DC current gain specified across two test conditions: h_FE1 (V_CE = 1 V, I_C = 100 mA) and h_FE2 (V_CE = 1 V, I_C = 300 mA), supporting both linear amplification and saturated switching modes.

It features a maximum collector-emitter breakdown voltage of 45 V under standard test conditions, emitter-base breakdown of 5 V, and a current gain bandwidth product (f_T) of 100 MHz - enabling operation in audio-frequency and low-speed digital circuits up to several megahertz.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	45 V - maximum safe collector-emitter voltage before breakdown in common-emitter configuration
I_C (DC)	800 mA - continuous collector current rating defining maximum load drive capability
P_D	625 mW - thermal power limit at 25°C ambient, derating 5 mW/°C above that temperature
h_FE	160–400 - guaranteed DC current gain range at V_CE = 1 V, I_C = 100 mA, critical for bias stability
V_CE(sat)	0.7 V - collector-emitter saturation voltage at I_C = 500 mA, I_B = 50 mA, determining on-state power loss
f_T	100 MHz - frequency at which small-signal current gain drops to unity, limiting high-frequency amplification

Pinout & Package

BC33725TF uses the industry-standard TO-92 3-lead plastic package with straight leads and tape-and-reel packaging (T&R). Pin numbering follows JEDEC TO-92 orientation: flat side facing user, leads down, left-to-right = Emitter (1), Base (2), Collector (3).

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current exit path for majority carriers	Connected to ground or low-impedance return; defines reference node for biasing
2 (Base)	Control terminal for minority carrier injection	Receives input current to modulate collector current; requires series resistor for current limiting
3 (Collector)	Current entry path for majority carriers	Connected to load or supply rail; handles switched/sourced current up to 800 mA

Key Features

Feature	Design Value
Switching & amplification dual-use	Validated by h_FE range and V_CE(sat) ≤ 0.7 V, enabling reliable operation in both active and saturation regions
Complementary pairing with BC327/BC328	Enables push-pull output stages without redesign due to matched voltage/current ratings and inverted polarity
TO-92 mechanical compatibility	Ensures drop-in replacement in legacy through-hole PCB layouts designed for standard 3-lead TO-92 footprints
100 MHz f_T	Supports audio preamplifier and low-speed digital interface applications up to ~10 MHz with usable gain margin

Applications

Audio Frequency Driver	Digital Logic Level Shifting
Use Scenario: Driving 8 Ω speaker loads in portable audio amplifiers with single-supply rails up to ±12 V. IC Role / Device Role / Timing Role: NPN transistor configured in common-emitter amplifier topology to deliver 100–300 mW output power. Use Value: Delivers sufficient current gain (h_FE ≥ 160) and low V_CE(sat) to minimize distortion and thermal rise at 100–300 mA peak output.	Use Scenario: Interfacing 3.3 V microcontroller GPIO to 5 V TTL logic inputs in mixed-voltage embedded systems. IC Role / Device Role / Timing Role: NPN switch operating in saturation to translate logic HIGH from 3.3 V domain to 5 V domain. Use Value: Achieves <100 ns turn-on/off with 0.7 V V_CE(sat) and 100 MHz f_T, ensuring clean level translation without timing skew.
Low-Power Relay Driver	LED Current Switching
Use Scenario: Controlling 12 V, 400 mA coil relays in industrial control panels using MCU outputs. IC Role / Device Role / Timing Role: Saturated switch providing base-driven current gain to activate relay coil without MCU overloading. Use Value: Supports 800 mA I_C rating and 625 mW P_D, allowing safe 400 mA relay drive with 2× thermal margin at ambient temperatures ≤ 60°C.	Use Scenario: Switching 20–100 mA LED strings in indicator panels and status displays. IC Role / Device Role / Timing Role: Constant-current switch regulating LED brightness via base current control in common-emitter configuration. Use Value: Maintains stable LED current across supply variations due to h_FE consistency (160–400) and low V_BE(on) of 1.2 V at 300 mA.

Audio Frequency Driver

Digital Logic Level Shifting

Use Scenario: Driving 8 Ω speaker loads in portable audio amplifiers with single-supply rails up to ±12 V.

IC Role / Device Role / Timing Role: NPN transistor configured in common-emitter amplifier topology to deliver 100–300 mW output power.

Use Value: Delivers sufficient current gain (h_FE ≥ 160) and low V_CE(sat) to minimize distortion and thermal rise at 100–300 mA peak output.

Use Scenario: Interfacing 3.3 V microcontroller GPIO to 5 V TTL logic inputs in mixed-voltage embedded systems.

IC Role / Device Role / Timing Role: NPN switch operating in saturation to translate logic HIGH from 3.3 V domain to 5 V domain.

Use Value: Achieves <100 ns turn-on/off with 0.7 V V_CE(sat) and 100 MHz f_T, ensuring clean level translation without timing skew.

Low-Power Relay Driver

LED Current Switching

Use Scenario: Controlling 12 V, 400 mA coil relays in industrial control panels using MCU outputs.

IC Role / Device Role / Timing Role: Saturated switch providing base-driven current gain to activate relay coil without MCU overloading.

Use Value: Supports 800 mA I_C rating and 625 mW P_D, allowing safe 400 mA relay drive with 2× thermal margin at ambient temperatures ≤ 60°C.

Use Scenario: Switching 20–100 mA LED strings in indicator panels and status displays.

IC Role / Device Role / Timing Role: Constant-current switch regulating LED brightness via base current control in common-emitter configuration.

Use Value: Maintains stable LED current across supply variations due to h_FE consistency (160–400) and low V_BE(on) of 1.2 V at 300 mA.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC337-25 (ON Semi)	Same h_FE bin (160–400), identical absolute max ratings, but supplied in bulk or ammo pack - no T&R option	No functional difference; differs only in packaging format and reel compatibility	Select BC33725TF when automated pick-and-place assembly requires tape-and-reel delivery
PN2222A (ON Semi)	Lower h_FE (100–300), same V_CEO (40 V), higher V_CE(sat) (1.2 V @ 500 mA), same TO-92 package	Less suitable for low-distortion audio drivers due to lower gain and higher saturation voltage	Choose PN2222A only if cost sensitivity outweighs gain and saturation performance requirements

Compared with BC33725TF, BC337-25 offers identical electrical behavior but lacks tape-and-reel packaging, while PN2222A trades 30% lower h_FE and 71% higher V_CE(sat) for broader legacy availability - making BC33725TF optimal for automated production of audio and logic interface circuits requiring consistent gain and low-loss switching.

Availability

BC33725TF is available at Aetrix Electronics and suitable for audio driver stages, digital level-shifting interfaces, low-power relay control, and LED current switching requiring stable component supply and tape-and-reel compatibility for SMT assembly lines.

Supply support for BC33725TF 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 is a global semiconductor manufacturer specializing in energy-efficient power and signal management solutions, with roots in Fairchild Semiconductor's analog and discrete portfolio.

The BC33725TF belongs to the BC337/BC338 family of general-purpose NPN transistors designed for cost-sensitive, high-volume consumer and industrial applications requiring reliable low-power switching and amplification.

FAQ

What is the maximum collector-emitter voltage rating for BC33725TF?

The BC33725TF has a maximum collector-emitter voltage (V_CEO) rating of 45 V under standard test conditions (I_C = 10 mA, I_B = 0). This value defines the upper limit for safe operation in common-emitter configurations. Exceeding 45 V risks avalanche breakdown and permanent device damage. The BC33725TF also supports a higher V_CES of 50 V under pulsed conditions (I_C = 0.1 mA, V_BE = 0), but sustained operation must remain within the 45 V V_CEO limit.

Does BC33725TF have a guaranteed DC current gain range?

Yes, the BC33725TF is binned to h_FE Class 25, guaranteeing a DC current gain (h_FE1) between 160 and 400 when measured at V_CE = 1 V and I_C = 100 mA. This range ensures predictable biasing in amplifier and switching designs. At higher current (I_C = 300 mA), h_FE2 remains ≥100, supporting robust operation across varying load conditions. The BC33725TF's h_FE specification is validated per the official ON Semiconductor datasheet Rev. 1.5.

What package type and lead configuration does BC33725TF use?

The BC33725TF uses the TO-92 3-lead plastic package with straight leads and is supplied in tape-and-reel format (T&R). Pinout follows JEDEC standard: with the flat side facing the user and leads pointing downward, the leftmost pin is Emitter (1), center is Base (2), and rightmost is Collector (3). This configuration matches legacy BC337 designs and ensures mechanical compatibility with existing TO-92 footprints on through-hole PCBs.

Can BC33725TF replace BC337-25 in existing designs?

Yes, BC33725TF is functionally identical to BC337-25 in all electrical and thermal specifications - including V_CEO, I_C, h_FE, and package dimensions. The only difference is packaging: BC33725TF is supplied in tape-and-reel for automated assembly, whereas BC337-25 is offered in bulk or ammo pack. No circuit or layout changes are required when substituting BC33725TF into designs originally specifying BC337-25, provided the assembly process supports T&R feeders.

What is the thermal resistance and power derating behavior of BC33725TF?

The BC33725TF has a junction-to-ambient thermal resistance (R_θJA) of 200°C/W under standard FR-4 PCB conditions (76 mm × 114 mm, minimum land pattern). Its maximum power dissipation is 625 mW at 25°C ambient, with linear derating of 5.0 mW/°C above that temperature. This means usable power drops to 500 mW at 50°C ambient and 375 mW at 75°C - critical for thermal design in enclosed or high-temperature environments where the BC33725TF operates near its 150°C maximum junction temperature.

BC33725TF Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Packaging:: Tape & Reel (TR)

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:: 100MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

BC33725TF FAQ

1.How can I place an order for BC33725TF through Aetrix?

Please submit a Request for Quotation (RFQ) for BC33725TF 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 BC33725TF reliable?

The price and inventory of BC33725TF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC33725TF is usually 5 days.

3.What payment methods are accepted for BC33725TF?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC33725TF transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC33725TF?

BC33725TF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC33725TF 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 BC33725TF?

For technical support, including BC33725TF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC33725TF requirements.

6.How does Aetrix verify that BC33725TF is sourced from the original manufacturer or authorized distributors?

All BC33725TF 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 BC33725TF meets industry standards.

7.What is the process for return or replacement of BC33725TF?

All BC33725TF units undergo pre-shipment inspection (PSI). If there is an issue with BC33725TF, 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 BC33725TF part is unused and in its original packaging.

Return procedure for BC33725TF:

1.Submit a request within 90 days.

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

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