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

onsemi 2N4403_D81Z

Name: 2N4403_D81Z
Brand: onsemi
SKU: 2N4403_D81Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2N4403_D81Z

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: 2N4403_D81Z.pdf

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

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Product details

Overview

2N4403_D81Z from Fairchild Semiconductor is a PNP general-purpose bipolar junction transistor used as an amplifier or switch in low-to-medium power linear and switching 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 supports applications such as signal inversion, relay driving, and discrete logic interfacing.

For engineers reviewing the 2N4403_D81Z datasheet, pinout, applications, or equivalent options, key selection criteria include verified PNP polarity, guaranteed V_CEO/V_CBO = 40 V rating, confirmed 600 mA continuous collector current capability, thermal resistance R_θJA = 200°C/W (TO-92), and documented switching times (t_d = 15 ns, t_s = 225 ns) under standard test conditions.

Technical Context

The 2N4403_D81Z is a silicon PNP BJT optimized for general-purpose amplification and saturated switching. Its DC current gain (h_FE) ranges from 30 to 300 depending on collector current, and it delivers V_CE(sat) = 0.4 V at I_C = 150 mA / I_B = 15 mA, supporting efficient low-voltage switching.

Small-signal parameters include f_T = 200 MHz at I_C = 20 mA, C_cb = 8.5 pF, and C_eb = 30 pF - enabling use in audio-frequency amplifiers and moderate-speed digital interfaces. Thermal design is constrained by R_θJA = 200°C/W and maximum junction temperature of +150°C.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	40 V - Maximum safe collector-emitter voltage before breakdown; defines upper rail limit in PNP switch/amplifier stages.
I_C (continuous)	600 mA - Absolute max DC collector current; usable up to 500 mA per functional description without derating.
h_FE	100 (at I_C = 10 mA, V_CE = 1.0 V) - Confirmed DC current gain for biasing stable Class-A amplifiers or calculating base drive.
f_T	200 MHz - Unity-gain bandwidth; validates suitability for audio amplification and sub-100 MHz switching.
t_s (storage time)	225 ns - Measured at V_CC = 30 V, I_C = 150 mA; critical for turn-off delay in saturated switching applications.
R_θJA	200 °C/W - Junction-to-ambient thermal resistance in TO-92; determines required heatsinking or ambient derating above 25°C.
P_D	625 mW - Total device dissipation at T_A = 25°C; drops linearly at 5.0 mW/°C above 25°C.

Pinout & Package

2N4403_D81Z is housed in a through-hole TO-92 package with standardized lead configuration: Emitter (E), Base (B), Collector (C) arranged left-to-right when viewing the flat side with leads downward.

Pin/Terminal	Circuit Role	Design Meaning
E (Emitter)	Current source terminal for PNP operation	Connected to higher potential rail in common-emitter switches; sets reference for base bias network.
B (Base)	Control input for minority-carrier injection	Receives current-limited drive to saturate or cut off; requires ~1/10th of I_C for hard saturation.
C (Collector)	Current sink terminal	Typically tied to load and ground-return path; voltage swing limited by V_CEO = 40 V rating.

Key Features

Feature	Design Value
High f_T bandwidth	200 MHz enables stable small-signal amplification up to mid-VHF range without external compensation.
Low V_CE(sat)	0.4 V at I_C = 150 mA reduces conduction loss and self-heating in switching regulators and driver stages.
Wide temperature range	–55°C to +150°C operation supports deployment in automotive engine compartments and industrial control enclosures.
Verified switching performance	Documented t_d/t_r/t_s/t_f values allow accurate timing budgeting in discrete logic and pulse-width modulation circuits.

Applications

Audio Signal Amplification	Discrete Logic Level Shifting
Use Scenario: Amplifying line-level analog signals in preamplifier stages or active filters before ADC sampling. IC Role / Device Role / Timing Role: PNP common-emitter amplifier providing inverted gain with low distortion and wide bandwidth. Use Value: Delivers h_FE ≥ 60 and f_T = 200 MHz to maintain fidelity up to 20 kHz with minimal phase shift.	Use Scenario: Converting 3.3 V logic outputs to interface with 5 V or 12 V legacy peripherals or optocouplers. IC Role / Device Role / Timing Role: Saturated PNP switch acting as active-low level translator with fast edge response. Use Value: Achieves t_r = 20 ns and t_f = 30 ns to preserve signal integrity in 1–5 MHz digital control lines.
Relay Driver Circuit	Current Mirror Reference
Use Scenario: Driving electromagnetic relays requiring 50–200 mA coil current in PLC I/O modules or HVAC controllers. IC Role / Device Role / Timing Role: High-current PNP switch operating in saturation to minimize power loss and heat generation. Use Value: Supports I_C = 500 mA with V_CE(sat) ≤ 0.75 V, reducing relay coil heating and improving contact lifetime.	Use Scenario: Building matched current sources in analog sensor conditioning circuits or bias networks for op-amps. IC Role / Device Role / Timing Role: Discrete PNP element in emitter-degenerated mirror topology for stable DC current replication. Use Value: Maintains h_FE consistency across temperature (–55°C to +150°C), enabling <1% current error over full industrial range.

Audio Signal Amplification

Discrete Logic Level Shifting

Use Scenario: Amplifying line-level analog signals in preamplifier stages or active filters before ADC sampling.

IC Role / Device Role / Timing Role: PNP common-emitter amplifier providing inverted gain with low distortion and wide bandwidth.

Use Value: Delivers h_FE ≥ 60 and f_T = 200 MHz to maintain fidelity up to 20 kHz with minimal phase shift.

Use Scenario: Converting 3.3 V logic outputs to interface with 5 V or 12 V legacy peripherals or optocouplers.

IC Role / Device Role / Timing Role: Saturated PNP switch acting as active-low level translator with fast edge response.

Use Value: Achieves t_r = 20 ns and t_f = 30 ns to preserve signal integrity in 1–5 MHz digital control lines.

Relay Driver Circuit

Current Mirror Reference

Use Scenario: Driving electromagnetic relays requiring 50–200 mA coil current in PLC I/O modules or HVAC controllers.

IC Role / Device Role / Timing Role: High-current PNP switch operating in saturation to minimize power loss and heat generation.

Use Value: Supports I_C = 500 mA with V_CE(sat) ≤ 0.75 V, reducing relay coil heating and improving contact lifetime.

Use Scenario: Building matched current sources in analog sensor conditioning circuits or bias networks for op-amps.

IC Role / Device Role / Timing Role: Discrete PNP element in emitter-degenerated mirror topology for stable DC current replication.

Use Value: Maintains h_FE consistency across temperature (–55°C to +150°C), enabling <1% current error over full industrial range.

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
MMBT4403	SOT-23 surface-mount package; lower P_D = 350 mW; R_θJA = 357°C/W; identical electrical specs.	Used where board space is constrained and reflow assembly is preferred; not drop-in compatible with TO-92 footprint.	Select MMBT4403 only when layout supports SMT and thermal management accounts for higher R_θJA.
2N3906	Lower I_C = 200 mA; V_CEO = 40 V; h_FE = 100 (at I_C = 10 mA); f_T = 250 MHz; TO-92 package.	Suitable for low-power signal switching but insufficient for >200 mA loads; faster but less robust in high-current drive.	Choose 2N3906 only for signal-level tasks below 150 mA; avoid for relay or lamp drivers requiring >200 mA.

Compared with MMBT4403 and 2N3906, the 2N4403_D81Z provides the highest continuous collector current (600 mA) in a through-hole TO-92 package, making it uniquely suited for medium-power discrete switching where solderability, serviceability, and thermal margin are prioritized over miniaturization.

Availability

2N4403_D81Z is available at Aetrix Electronics and suitable for relay driver circuits, audio preamplifiers, discrete logic translators, and industrial sensor interface modules requiring stable component supply and long-term manufacturability.

Supply support for 2N4403_D81Z 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 components before its acquisition by ON Semiconductor in 2016.

The 2N4403_D81Z belongs to Fairchild's legacy general-purpose BJT product line, designed specifically for cost-sensitive, high-reliability linear amplification and saturated switching in industrial, consumer, and automotive auxiliary systems.

FAQ

What is the maximum collector current rating for the 2N4403_D81Z?

The 2N4403_D81Z has an absolute maximum continuous collector current (I_C) of 600 mA, with functional operation validated up to 500 mA in switching and amplification roles. Derating is required above 25°C ambient per the 5.0 mW/°C thermal coefficient, and pulsed operation must follow factory guidance due to storage time limitations.

Is the 2N4403_D81Z pin-compatible with the MMBT4403?

No, the 2N4403_D81Z is not pin-compatible with the MMBT4403. While both share identical electrical characteristics, the 2N4403_D81Z uses a TO-92 through-hole package with E-B-C lead order, whereas the MMBT4403 uses an SOT-23 surface-mount package with different pinout and footprint. PCB redesign is required for substitution.

What is the typical storage time (t_s) of the 2N4403_D81Z under standard test conditions?

The 2N4403_D81Z exhibits a typical storage time (t_s) of 225 ns when tested at V_CC = 30 V, I_C = 150 mA, and I_B1 = I_B2 = 15 mA. This value is critical for estimating total turn-off delay in saturated switching applications and must be included in timing budgets for PWM or digital logic interfacing.

Does the 2N4403_D81Z support operation at elevated temperatures?

Yes, the 2N4403_D81Z is rated for junction temperatures from –55°C to +150°C and ambient operation across the same range. Its thermal resistance R_θJA = 200°C/W (TO-92) allows reliable function in industrial environments, provided power dissipation remains within derated limits - e.g., ≤400 mW at 75°C ambient.

Can the 2N4403_D81Z be used in linear amplifier configurations?

Yes, the 2N4403_D81Z is explicitly characterized for linear amplification, with h_FE specified across multiple I_C points, f_T = 200 MHz, and small-signal parameters (h_ie, h_fe, h_oe) provided at 1 kHz. Its low V_CE(sat) and stable gain make it suitable for Class-A audio preamplifiers and sensor signal conditioning stages.

2N4403_D81Z 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_D81Z FAQ

1.How can I place an order for 2N4403_D81Z through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N4403_D81Z 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_D81Z reliable?

The price and inventory of 2N4403_D81Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N4403_D81Z is usually 5 days.

3.What payment methods are accepted for 2N4403_D81Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N4403_D81Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N4403_D81Z?

2N4403_D81Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N4403_D81Z 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_D81Z?

For technical support, including 2N4403_D81Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N4403_D81Z requirements.

6.How does Aetrix verify that 2N4403_D81Z is sourced from the original manufacturer or authorized distributors?

All 2N4403_D81Z 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_D81Z meets industry standards.

7.What is the process for return or replacement of 2N4403_D81Z?

All 2N4403_D81Z units undergo pre-shipment inspection (PSI). If there is an issue with 2N4403_D81Z, 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_D81Z part is unused and in its original packaging.

Return procedure for 2N4403_D81Z:

1.Submit a request within 90 days.

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

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