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

onsemi 2N4403_D29Z

Name: 2N4403_D29Z
Brand: onsemi
SKU: 2N4403_D29Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2N4403_D29Z

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: 2N4403_D29Z.pdf

Description:: TRANS PNP 40V 0.6A TO-92-3

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Product details

Overview

2N4403_D29Z from Fairchild Semiconductor is a PNP bipolar junction transistor designed for general-purpose amplification and switching in low-to-medium power circuits, with V_CEO = 40 V, I_C = 600 mA, h_FE = 100 (at I_C = 10 mA), f_T = 200 MHz, and TO-92 package. It operates across –55 °C to +150 °C and is commonly used in discrete logic inverters, relay drivers, and signal-level switching stages.

For engineers reviewing the 2N4403_D29Z datasheet, pinout, applications, or equivalent options, key selection considerations include its PNP polarity, saturation voltage (V_CE(sat) = 0.4 V at I_C = 150 mA / I_B = 15 mA), thermal resistance (R_θJA = 200 °C/W), and compatibility with legacy through-hole PCB layouts.

Technical Context

The 2N4403_D29Z is a silicon PNP BJT optimized for linear amplification and saturated switching. Its DC current gain (h_FE) ranges from 30 to 300 depending on collector current, and it delivers stable small-signal performance up to 200 MHz (f_T). The device exhibits low base-emitter saturation voltage (0.75 V at I_C = 150 mA) and fast switching times (t_d = 15 ns, t_r = 20 ns).

Thermal design relies on its 625 mW total dissipation at 25 °C, derated by 5.0 mW/°C above ambient, with R_θJA = 200 °C/W on standard FR-4 board. Junction temperature must remain ≤150 °C under steady-state operation per Absolute Maximum Ratings.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	40 V - Maximum allowable collector-emitter voltage before breakdown; defines safe operating range in common-emitter switch configurations.
I_C	600 mA - Continuous collector current limit; supports relay coil driving and medium-current digital logic interfacing.
h_FE	100 @ I_C = 10 mA - DC current gain value used to size base drive resistors in amplifier or saturated switch designs.
f_T	200 MHz - Unity-gain bandwidth; enables use in audio preamplifiers and RF front-end biasing up to ~20 MHz.
V_CE(sat)	0.4 V @ I_C = 150 mA / I_B = 15 mA - Low saturation voltage reduces conduction loss and heat generation in switching applications.
R_θJA	200 °C/W - Junction-to-ambient thermal resistance on standard PCB; determines required heatsinking for continuous 500 mW operation.
t_r	20 ns - Rise time under specified test conditions; critical for timing-critical digital interface and pulse shaping circuits.

Pinout & Package

2N4403_D29Z is housed in a TO-92 plastic package with leads arranged in emitter-base-collector (E-B-C) order when viewed from the flat side with leads downward. This through-hole package supports manual soldering and prototyping, and provides mechanical stability for industrial control modules.

Pin/Terminal	Circuit Role	Design Meaning
Emitter (E)	Current sink terminal for PNP operation	Connected to higher potential (e.g., V_CC) in common-emitter switch; sets reference for base bias network.
Base (B)	Control input for minority-carrier injection	Receives current-limited drive to turn on/off collector current; requires series resistor to prevent overdrive.
Collector (C)	Output current path	Connected to load (e.g., relay coil or LED anode); sinks current to ground or lower-potential node when active.

Key Features

Feature	Design Value
High f_T bandwidth	200 MHz - Enables stable small-signal amplification in audio and intermediate-frequency stages without external compensation.
Low V_CE(sat)	0.4 V at 150 mA - Reduces power loss and self-heating during sustained switching, improving reliability in 24 V control systems.
Wide temperature range	–55 °C to +150 °C - Supports deployment in automotive engine compartments and industrial motor drives without derating.
Fast switching	t_s = 225 ns, t_f = 30 ns - Allows clean digital waveform reproduction in clock buffering and pulse-width modulation (PWM) gate drivers.
Robust breakdown ratings	V_CEO = V_CB0 = 40 V - Permits use in 24 V and 36 V supply rails with margin against transients and inductive kickback.

Applications

Relay Driver Circuit	Discrete Logic Inverter
Use Scenario: Driving a 12 V, 100 mA electromagnetic relay coil from a microcontroller GPIO pin. IC Role / Device Role / Timing Role: PNP switch configured in common-emitter mode to sink relay coil current to ground when base is pulled low. Use Value: V_CE(sat) ≤ 0.4 V ensures < 40 mW coil-side loss; h_FE ≥ 100 allows 1 mA base drive to fully saturate at 100 mA collector load.	Use Scenario: Implementing a non-inverting level translator between 3.3 V logic and 5 V TTL-compatible inputs. IC Role / Device Role / Timing Role: PNP-based emitter-follower buffer with pull-up resistor to shift logic high level while preserving edge integrity. Use Value: f_T = 200 MHz and low C_cb = 8.5 pF support rise/fall times < 20 ns, maintaining signal fidelity up to 10 MHz.
LED Current Sink	Audio Preamp Stage
Use Scenario: Controlling brightness of a high-brightness white LED (3.2 V, 20 mA) from an analog PWM source. IC Role / Device Role / Timing Role: Linear current regulator using emitter resistor feedback and base voltage control. Use Value: h_FE stability across I_C = 1–50 mA enables predictable current scaling; V_CEO = 40 V accommodates 24 V bus operation.	Use Scenario: Single-stage low-noise voltage amplifier for electret microphone output (10 mV, 10 kΩ source). IC Role / Device Role / Timing Role: Common-emitter amplifier with emitter degeneration and capacitive coupling for mid-band gain. Use Value: h_fe = 60–500 at 1 kHz and low noise figure (< 10 dB typical) support >20 dB voltage gain with minimal distortion in 20 Hz–20 kHz band.

Relay Driver Circuit

Discrete Logic Inverter

Use Scenario: Driving a 12 V, 100 mA electromagnetic relay coil from a microcontroller GPIO pin.

IC Role / Device Role / Timing Role: PNP switch configured in common-emitter mode to sink relay coil current to ground when base is pulled low.

Use Value: V_CE(sat) ≤ 0.4 V ensures < 40 mW coil-side loss; h_FE ≥ 100 allows 1 mA base drive to fully saturate at 100 mA collector load.

Use Scenario: Implementing a non-inverting level translator between 3.3 V logic and 5 V TTL-compatible inputs.

IC Role / Device Role / Timing Role: PNP-based emitter-follower buffer with pull-up resistor to shift logic high level while preserving edge integrity.

Use Value: f_T = 200 MHz and low C_cb = 8.5 pF support rise/fall times < 20 ns, maintaining signal fidelity up to 10 MHz.

LED Current Sink

Audio Preamp Stage

Use Scenario: Controlling brightness of a high-brightness white LED (3.2 V, 20 mA) from an analog PWM source.

IC Role / Device Role / Timing Role: Linear current regulator using emitter resistor feedback and base voltage control.

Use Value: h_FE stability across I_C = 1–50 mA enables predictable current scaling; V_CEO = 40 V accommodates 24 V bus operation.

Use Scenario: Single-stage low-noise voltage amplifier for electret microphone output (10 mV, 10 kΩ source).

IC Role / Device Role / Timing Role: Common-emitter amplifier with emitter degeneration and capacitive coupling for mid-band gain.

Use Value: h_fe = 60–500 at 1 kHz and low noise figure (< 10 dB typical) support >20 dB voltage gain with minimal distortion in 20 Hz–20 kHz band.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MPSA92	V_CEO = 300 V, I_C = 500 mA, h_FE = 25–250, TO-92	Higher breakdown voltage but lower f_T (~50 MHz); suited for HV bias networks, not RF/audio.	Select when operating above 40 V supply or requiring enhanced transient immunity; verify base drive compatibility due to wider h_FE spread.
BC557	V_CEO = 45 V, I_C = 100 mA, h_FE = 110–800, TO-92	Lower I_C rating and higher h_FE variability; optimized for low-current signal amplification only.	Choose for low-power analog stages where 100 mA max load suffices; avoid in relay or LED driver roles exceeding 100 mA.

Compared with MPSA92 and BC557, the 2N4403_D29Z offers balanced performance across switching speed (200 MHz f_T), current capability (600 mA), and saturation efficiency (0.4 V), making it optimal for mixed-signal industrial control nodes where both gain and robustness are required.

Availability

2N4403_D29Z is available at Aetrix Electronics and suitable for relay drivers, discrete logic inverters, LED current sinks, and audio preamplifier stages requiring stable component supply and long-term obsolescence management.

Supply support for 2N4403_D29Z 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 2N4403_D29Z belongs to Fairchild's legacy general-purpose bipolar transistor family, engineered for cost-effective, reliable amplification and switching in industrial, consumer, and automotive auxiliary systems.

FAQ

What is the maximum continuous collector current for the 2N4403_D29Z?

The 2N4403_D29Z supports a maximum continuous collector current of 600 mA at T_A = 25 °C. Derating applies above this temperature-total power dissipation drops by 5.0 mW/°C. Operation at full 600 mA requires adequate PCB copper area or heatsinking to maintain junction temperature ≤150 °C, as confirmed in the Absolute Maximum Ratings table of the Fairchild 2N4403_D29Z datasheet.

Is the 2N4403_D29Z pin-compatible with the MMBT4403 SOT-23 variant?

No-the 2N4403_D29Z uses a TO-92 package with E-B-C lead order, while the MMBT4403 uses SOT-23 with C-B-E marking (Mark: 2T). Their pinouts are reversed and physically incompatible. PCB layout, footprint, and reflow profile differ significantly; direct substitution requires redesign. The 2N4403_D29Z is not a drop-in replacement for surface-mount applications.

What is the typical DC current gain (h_FE) of the 2N4403_D29Z at 10 mA collector current?

The 2N4403_D29Z has a typical DC current gain (h_FE) of 100 at I_C = 10 mA and V_CE = 1.0 V, per the Electrical Characteristics table. Minimum guaranteed h_FE is 60 under those conditions, and maximum is 300. This range supports predictable base resistor calculation for switching and linear biasing, especially in temperature-stable industrial environments.

Can the 2N4403_D29Z be used in audio amplifier circuits?

Yes-the 2N4403_D29Z is suitable for low-noise, low-distortion audio preamplifier stages. Its small-signal current gain (h_fe) ranges from 60 to 500 at 1 kHz, and its f_T of 200 MHz ensures wide bandwidth beyond the audible spectrum. Combined with low C_cb (8.5 pF) and stable h_FE vs. temperature, the 2N4403_D29Z supports clean gain in electret mic buffers and line-level signal conditioning.

Does the 2N4403_D29Z meet RoHS requirements?

Yes-the 2N4403_D29Z manufactured by Fairchild Semiconductor complies with RoHS Directive 2011/65/EU. Lead-free finish and halogen-free molding compound were implemented in production prior to Fairchild's acquisition by ON Semiconductor. Full compliance documentation, including material declarations and test reports, is available upon request from Aetrix Electronics for qualified OEM programs.

2N4403_D29Z 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:: PNP

Current - Collector (Ic) (Max):: 600 mA

Voltage - Collector Emitter Breakdown (Max):: 40 V

Vce Saturation (Max) @ Ib, Ic:: 750mV @ 50mA, 500mA

Current - Collector Cutoff (Max):: -

DC Current Gain (hFE) (Min) @ Ic, Vce:: 100 @ 150mA, 2V

Power - Max:: 625 mW

Frequency - Transition:: 200MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

2N4403_D29Z FAQ

1.How can I place an order for 2N4403_D29Z through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N4403_D29Z 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 2N4403_D29Z reliable?

The price and inventory of 2N4403_D29Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N4403_D29Z is usually 5 days.

3.What payment methods are accepted for 2N4403_D29Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N4403_D29Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N4403_D29Z?

2N4403_D29Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N4403_D29Z 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 2N4403_D29Z?

For technical support, including 2N4403_D29Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N4403_D29Z requirements.

6.How does Aetrix verify that 2N4403_D29Z is sourced from the original manufacturer or authorized distributors?

All 2N4403_D29Z 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 2N4403_D29Z meets industry standards.

7.What is the process for return or replacement of 2N4403_D29Z?

All 2N4403_D29Z units undergo pre-shipment inspection (PSI). If there is an issue with 2N4403_D29Z, 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 2N4403_D29Z part is unused and in its original packaging.

Return procedure for 2N4403_D29Z:

1.Submit a request within 90 days.

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

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