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

onsemi 2N3704_D27Z

Name: 2N3704_D27Z
Brand: onsemi
SKU: 2N3704_D27Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2N3704_D27Z

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: 2N3704_D27Z.pdf

Description:: TRANS NPN 30V 0.5A TO-92-3

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Product details

Overview

2N3704_D27Z from Fairchild Semiconductor is an NPN epitaxial silicon transistor designed for general-purpose amplification and switching in low-to-medium power circuits, with V_CEO = 30 V, I_C = 500 mA continuous, h_FE = 100–300 at I_C = 50 mA, V_CE(sat) ≤ 1.0 V, and TO-92 package. It operates across –55°C to +150°C and supports applications such as signal buffering in audio preamps and digital logic interfacing.

For engineers reviewing the 2N3704_D27Z datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain range, saturation voltage under defined drive conditions, thermal resistance (R_θJA = 200°C/W), maximum collector-emitter breakdown voltage, and compatibility with through-hole PCB layouts using standard TO-92 footprints.

Technical Context

The 2N3704_D27Z is a discrete bipolar junction transistor fabricated using Fairchild's Process 10, optimized for linear amplification and saturated switching. Its h_FE variation (100–300) enables predictable biasing in Class-A amplifier stages, while f_T = 100 MHz supports small-signal operation up to mid-VHF frequencies.

Thermal design relies on its R_θJA = 200°C/W and P_D = 625 mW at 25°C, derating linearly at 5.0 mW/°C above ambient. The device exhibits low leakage (I_CBO, I_EBO ≤ 100 nA) and tight breakdown voltage specs (V_CEO = 30 V, V_CBO = 50 V), ensuring robustness in unregulated supply environments.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	30 V - Maximum safe collector-emitter voltage before avalanche breakdown; defines upper rail limit in common-emitter switch designs.
I_C (continuous)	500 mA - Continuous collector current handling; supports relay drivers and LED arrays without forced cooling.
h_FE	100–300 - DC current gain range at V_CE = 5 V, I_C = 50 mA; determines base drive resistor sizing for stable bias.
V_CE(sat)	0.5–1.0 V - Saturation voltage at I_C = 100 mA, I_B = 5 mA; directly impacts power loss and heating in switching mode.
f_T	100 MHz - Transition frequency; sets usable bandwidth limit for small-signal amplification stages.
R_θJA	200 °C/W - Junction-to-ambient thermal resistance; requires ≥ 0.5 cm² copper pour for sustained 300 mA operation at 70°C ambient.
T_J range	–55°C to +150°C - Operating junction temperature span; enables deployment in automotive under-hood and industrial control enclosures.

Pinout & Package

2N3704_D27Z is housed in a TO-92 plastic package with 3 leads, standardized for through-hole mounting and manual prototyping. Lead spacing matches JEDEC TO-92 outline, enabling compatibility with common breadboards and wave-solder fixtures.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal in NPN configuration	Connected to ground or low-side return path; base-emitter junction forward-biased during conduction.
2 (Collector)	Current source terminal	Typically tied to load and positive supply; carries full switched/amplified output current.
3 (Base)	Control input for minority-carrier injection	Receives current-limited drive (e.g., via 1–10 kΩ resistor); governs transistor turn-on/turn-off timing and gain.

Key Features

Feature	Design Value
High h_FE range	100–300 ensures reliable active-mode biasing across production lots without individual trimming.
Low V_CE(sat)	≤1.0 V at rated I_C/I_B minimizes conduction loss in 5–12 V logic-level switching applications.
Robust breakdown ratings	V_CBO = 50 V and V_CEO = 30 V provide margin against transients in inductive load switching.
Wide temperature operation	–55°C to +150°C junction range supports use in non-temperature-controlled industrial environments.
Low leakage currents	I_CBO, I_EBO ≤ 100 nA reduce standby power and improve stability in high-impedance bias networks.

Applications

Audio Signal Amplifier	Digital Logic Level Shifter
Use Scenario: Boosting weak line-level signals (e.g., from electret microphones or guitar pickups) prior to ADC sampling in embedded audio recorders. IC Role / Device Role / Timing Role: NPN common-emitter amplifier stage providing 20–30 dB voltage gain with minimal distortion at 1–10 kHz. Use Value: h_FE consistency and f_T = 100 MHz ensure flat frequency response and low noise in single-stage preamp topologies.	Use Scenario: Translating 3.3 V CMOS logic outputs to interface with 5 V TTL inputs in mixed-voltage microcontroller systems. IC Role / Device Role / Timing Role: Saturated NPN switch operating in cutoff/saturation, driven by GPIO pins with series base resistors. Use Value: V_CE(sat) ≤ 1.0 V guarantees valid LOW level (<0.8 V) at 5 V rail, meeting TTL input threshold requirements.
Relay Driver Circuit	LED Current Switch
Use Scenario: Controlling 12 V, 100 mA coil relays from microcontroller I/O pins in home automation controllers. IC Role / Device Role / Timing Role: Low-side switch with flyback diode protection, turning relay ON/OFF based on base drive pulses. Use Value: I_C = 500 mA rating provides 5× safety margin over typical relay coil current, preventing thermal runaway.	Use Scenario: Driving multiple 20 mA indicator LEDs from a single MCU port pin in industrial HMI panels. IC Role / Device Role / Timing Role: Constant-current switch regulating LED brightness via base-resistor-limited I_B and h_FE-determined I_C. Use Value: Tight h_FE distribution enables consistent LED intensity across units without per-channel calibration.

Audio Signal Amplifier

Digital Logic Level Shifter

Use Scenario: Boosting weak line-level signals (e.g., from electret microphones or guitar pickups) prior to ADC sampling in embedded audio recorders.

IC Role / Device Role / Timing Role: NPN common-emitter amplifier stage providing 20–30 dB voltage gain with minimal distortion at 1–10 kHz.

Use Value: h_FE consistency and f_T = 100 MHz ensure flat frequency response and low noise in single-stage preamp topologies.

Use Scenario: Translating 3.3 V CMOS logic outputs to interface with 5 V TTL inputs in mixed-voltage microcontroller systems.

IC Role / Device Role / Timing Role: Saturated NPN switch operating in cutoff/saturation, driven by GPIO pins with series base resistors.

Use Value: V_CE(sat) ≤ 1.0 V guarantees valid LOW level (<0.8 V) at 5 V rail, meeting TTL input threshold requirements.

Relay Driver Circuit

LED Current Switch

Use Scenario: Controlling 12 V, 100 mA coil relays from microcontroller I/O pins in home automation controllers.

IC Role / Device Role / Timing Role: Low-side switch with flyback diode protection, turning relay ON/OFF based on base drive pulses.

Use Value: I_C = 500 mA rating provides 5× safety margin over typical relay coil current, preventing thermal runaway.

Use Scenario: Driving multiple 20 mA indicator LEDs from a single MCU port pin in industrial HMI panels.

IC Role / Device Role / Timing Role: Constant-current switch regulating LED brightness via base-resistor-limited I_B and h_FE-determined I_C.

Use Value: Tight h_FE distribution enables consistent LED intensity across units without per-channel calibration.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
2N2222A	V_CEO = 40 V, h_FE = 100–300, P_D = 800 mW; higher breakdown and power rating.	Better suited for 24 V industrial control where 30 V margin is insufficient.	Select when higher V_CEO or thermal headroom is required; footprint differs slightly but remains TO-92 compatible.
BC547B	h_FE = 200–450, V_CEO = 45 V, I_C = 100 mA; higher gain but lower current capability.	Preferred in low-power analog stages where precision biasing outweighs current drive needs.	Choose for battery-powered sensor nodes requiring high gain at µA-level base currents; not suitable for >150 mA loads.

Compared with 2N3704_D27Z, the 2N2222A offers greater voltage and power headroom for ruggedized switching, while the BC547B trades current capacity for tighter gain control in low-noise amplifiers-neither is pin-compatible without layout verification, but all three share TO-92 mechanical compatibility.

Availability

2N3704_D27Z is available at Aetrix Electronics and suitable for audio preamplifiers, relay drivers, logic level shifters, and LED current switches requiring stable component supply across industrial and embedded design cycles.

Supply support for 2N3704_D27Z 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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete devices before its acquisition by ON Semiconductor in 2016.

The 2N3704_D27Z belongs to Fairchild's legacy general-purpose bipolar transistor family, engineered for cost-sensitive, medium-speed amplification and switching in consumer, industrial, and educational electronics.

FAQ

What is the maximum continuous collector current rating for the 2N3704_D27Z?

The 2N3704_D27Z has a maximum continuous collector current (I_C) rating of 500 mA at T_A = 25°C. This rating assumes adequate PCB copper area and ambient airflow; derating is required above 25°C per the 5.0 mW/°C thermal specification. Exceeding this current risks thermal runaway or permanent junction damage.

Does the 2N3704_D27Z support switching applications, and what is its typical V_CE(sat)?

Yes, the 2N3704_D27Z is qualified for switching use with V_CE(sat) = 0.5–1.0 V at I_C = 100 mA and I_B = 5 mA. This low saturation voltage ensures minimal power dissipation during ON-state operation, making it suitable for driving relays, LEDs, and other medium-current loads in digital interface circuits.

What package type does the 2N3704_D27Z use, and how are its leads arranged?

The 2N3704_D27Z uses a TO-92 plastic package with leads arranged as Emitter (pin 1), Collector (pin 2), Base (pin 3) when viewed with flat side facing outward and leads pointing downward. This orientation matches JEDEC standard TO-92 pinout and is verified in Fairchild's Rev. B datasheet from July 2002.

What is the DC current gain (h_FE) range for the 2N3704_D27Z, and under what conditions is it specified?

The 2N3704_D27Z exhibits h_FE = 100–300 when measured at V_CE = 5.0 V and I_C = 50 mA. This range reflects production lot variation and must be accounted for in bias network design-e.g., using emitter degeneration or feedback to maintain stability across gain extremes.

Can the 2N3704_D27Z operate reliably at elevated temperatures, and what is its junction temperature limit?

Yes, the 2N3704_D27Z supports operation from –55°C to +150°C junction temperature. Its absolute maximum T_J is 150°C, enforced by internal thermal design and packaging. Sustained operation near this limit requires careful thermal management, including PCB copper area and ambient temperature control, to avoid accelerated degradation.

2N3704_D27Z 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):: 500 mA

Voltage - Collector Emitter Breakdown (Max):: 30 V

Vce Saturation (Max) @ Ib, Ic:: 1V @ 5mA, 100mA

Current - Collector Cutoff (Max):: 100nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 100 @ 50mA, 5V

Power - Max:: 625 mW

Frequency - Transition:: 100MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

2N3704_D27Z FAQ

1.How can I place an order for 2N3704_D27Z through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N3704_D27Z 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 2N3704_D27Z reliable?

The price and inventory of 2N3704_D27Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N3704_D27Z is usually 5 days.

3.What payment methods are accepted for 2N3704_D27Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N3704_D27Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N3704_D27Z?

2N3704_D27Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N3704_D27Z 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 2N3704_D27Z?

For technical support, including 2N3704_D27Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N3704_D27Z requirements.

6.How does Aetrix verify that 2N3704_D27Z is sourced from the original manufacturer or authorized distributors?

All 2N3704_D27Z 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 2N3704_D27Z meets industry standards.

7.What is the process for return or replacement of 2N3704_D27Z?

All 2N3704_D27Z units undergo pre-shipment inspection (PSI). If there is an issue with 2N3704_D27Z, 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 2N3704_D27Z part is unused and in its original packaging.

Return procedure for 2N3704_D27Z:

1.Submit a request within 90 days.

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

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