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

onsemi PN3643_D27Z

Name: PN3643_D27Z
Brand: onsemi
SKU: PN3643_D27Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: PN3643_D27Z

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: PN3643_D27Z.pdf

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

Quantity:: RFQ Add To RFQ list

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Product details

Overview

PN3643_D27Z from Fairchild Semiconductor is an NPN general-purpose bipolar junction transistor (BJT) designed for 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 = 150 mA, and TO-92 package. It serves in audio preamplifiers, relay drivers, and logic-level interface circuits.

For engineers reviewing the PN3643_D27Z datasheet, pinout, applications, or equivalent options, key selection considerations include its DC current gain range, saturation voltage under defined drive conditions, thermal resistance (R_θJA = 200 °C/W), and suitability for 30 MHz small-signal amplifier use.

Technical Context

The PN3643_D27Z operates as a silicon NPN BJT with fixed-emitter configuration and base-controlled conduction. Its design supports both linear amplification (f = 30 MHz, G_pe = 10 dB) and saturated switching (V_CE(sat) = 0.22 V at I_C = 150 mA, I_B = 15 mA).

Thermal performance is defined by R_θJA = 200 °C/W and maximum junction temperature of 150 °C, requiring derating above 25 °C at 5.0 mW/°C. The device meets JEDEC TO-92 mechanical standards with 3-pin leaded through-hole mounting.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	30 V - Maximum allowable collector-emitter voltage before breakdown under open-base condition.
I_C (continuous)	500 mA - Maximum steady-state collector current without thermal failure at T_A = 25 °C.
h_FE	100–300 - DC current gain range at V_CE = 10 V, enabling predictable base drive sizing for switching.
V_CE(sat)	0.22 V - Low saturation voltage at I_C = 150 mA / I_B = 15 mA, minimizing conduction loss in switch mode.
R_θJA	200 °C/W - Junction-to-ambient thermal resistance, defining required PCB copper area or heatsinking for safe operation.
f_T	Not specified - Small-signal current gain cutoff frequency not provided in source documentation.

Pinout & Package

PN3643_D27Z is housed in a standard JEDEC TO-92 plastic package with 3 leads: Emitter (Pin 1), Base (Pin 2), Collector (Pin 3). Leads are spaced 1.27 mm apart, body length 4.58 mm max, and total device dissipation rated at 625 mW at 25 °C ambient.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current exit path for majority carriers	Connected to ground or low-impedance return in common-emitter configurations; sets reference for bias network.
2 (Base)	Control electrode for minority carrier injection	Receives current-limited drive signal; requires series resistor to limit I_B and ensure h_FE-based I_C control.
3 (Collector)	Current entry path and output terminal	Connected to load or supply rail; handles full switched current and must be routed with adequate trace width for 500 mA.

Key Features

Feature	Design Value
High DC current gain range	h_FE = 100–300 at I_C = 150 mA enables stable biasing across process variation and temperature.
Low V_CE(sat)	0.22 V at rated I_C/I_B reduces power loss and self-heating during switching duty cycles.
TO-92 mechanical compatibility	Standard 3-lead through-hole footprint allows direct replacement in legacy designs using similar NPN transistors.
Rated for 30 MHz operation	G_pe = 10 dB at f = 30 MHz confirms usable RF amplification capability in narrowband VHF applications.

Applications

Audio Preamp Stage	DC Motor Driver Interface
Use Scenario: Amplifying low-level microphone or line-level signals prior to ADC sampling in embedded audio systems. IC Role / Device Role / Timing Role: NPN BJT configured in common-emitter topology to provide voltage gain with minimal distortion. Use Value: h_FE ≥ 100 ensures sufficient gain margin; V_CE(sat) ≤ 0.22 V prevents clipping near rail limits in single-supply designs.	Use Scenario: Driving small brushed DC motors (≤ 5 W) in robotics or actuator modules via microcontroller GPIO. IC Role / Device Role / Timing Role: Switching element controlling motor current flow between supply and ground. Use Value: I_C = 500 mA rating supports typical stall currents; TO-92 mounting simplifies hand-soldered prototyping.
Relay Coil Driver	Logic-Level Translator
Use Scenario: Energizing 5 V or 12 V electromagnetic relays in industrial control panels or home automation hubs. IC Role / Device Role / Timing Role: Saturated switch interfacing low-current logic outputs to high-inductance relay coils. Use Value: V_CEO = 30 V withstands flyback spikes up to 2× supply; R_θJA = 200 °C/W permits intermittent 100% duty cycle operation.	Use Scenario: Converting 3.3 V CMOS logic levels to 5 V TTL-compatible signals in mixed-voltage digital subsystems. IC Role / Device Role / Timing Role: Active pull-up stage with emitter-follower or common-collector configuration. Use Value: V_EBO = 5.0 V allows safe base-emitter reverse bias during level transitions; h_FE stability ensures consistent output impedance.

Audio Preamp Stage

DC Motor Driver Interface

Use Scenario: Amplifying low-level microphone or line-level signals prior to ADC sampling in embedded audio systems.

IC Role / Device Role / Timing Role: NPN BJT configured in common-emitter topology to provide voltage gain with minimal distortion.

Use Value: h_FE ≥ 100 ensures sufficient gain margin; V_CE(sat) ≤ 0.22 V prevents clipping near rail limits in single-supply designs.

Use Scenario: Driving small brushed DC motors (≤ 5 W) in robotics or actuator modules via microcontroller GPIO.

IC Role / Device Role / Timing Role: Switching element controlling motor current flow between supply and ground.

Use Value: I_C = 500 mA rating supports typical stall currents; TO-92 mounting simplifies hand-soldered prototyping.

Relay Coil Driver

Logic-Level Translator

Use Scenario: Energizing 5 V or 12 V electromagnetic relays in industrial control panels or home automation hubs.

IC Role / Device Role / Timing Role: Saturated switch interfacing low-current logic outputs to high-inductance relay coils.

Use Value: V_CEO = 30 V withstands flyback spikes up to 2× supply; R_θJA = 200 °C/W permits intermittent 100% duty cycle operation.

Use Scenario: Converting 3.3 V CMOS logic levels to 5 V TTL-compatible signals in mixed-voltage digital subsystems.

IC Role / Device Role / Timing Role: Active pull-up stage with emitter-follower or common-collector configuration.

Use Value: V_EBO = 5.0 V allows safe base-emitter reverse bias during level transitions; h_FE stability ensures consistent output impedance.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMBT3904LT1G	SMD SOT-23 package; lower I_C = 200 mA; h_FE = 100–300 at I_C = 10 mA.	Not suitable for 500 mA loads; better for high-density PCBs and automated assembly.	Select when board space is constrained and load current ≤ 200 mA.
2N3904	Same TO-92 package; identical pinout; I_C = 200 mA; V_CEO = 40 V; h_FE = 100–300 at I_C = 10 mA.	Lower current rating limits use in higher-power switching; higher V_CEO improves margin in 36 V systems.	Select when V_CEO > 30 V is required and I_C ≤ 200 mA suffices.

Compared with MMBT3904LT1G and 2N3904, PN3643_D27Z uniquely supports 500 mA continuous collector current in TO-92 while maintaining compatible h_FE and V_CE(sat), making it optimal for medium-power through-hole switching where thermal management permits.

Availability

PN3643_D27Z is available at Aetrix Electronics and suitable for audio preamplifiers, relay coil drivers, and DC motor interface circuits requiring stable component supply and long-term industrial availability.

Supply support for PN3643_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 manufacturer specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.

PN3643_D27Z belongs to Fairchild's general-purpose NPN transistor product line, engineered for cost-sensitive, medium-current amplification and switching in consumer, industrial, and automotive-qualified auxiliary circuits.

FAQ

What is the maximum continuous collector current rating for PN3643_D27Z?

The PN3643_D27Z has a maximum continuous collector current (I_C) rating of 500 mA at T_A = 25 °C. This rating decreases with rising ambient temperature due to thermal derating at 5.0 mW/°C above 25 °C, and operation must remain within the 150 °C maximum junction temperature limit. The PN3643_D27Z datasheet specifies this value under steady-state DC conditions.

Does PN3643_D27Z have a documented V_CE(sat) specification, and under what test conditions?

Yes, PN3643_D27Z specifies V_CE(sat) = 0.22 V under test conditions of I_C = 150 mA and I_B = 15 mA. This value reflects the transistor's on-state voltage drop when fully saturated, directly impacting conduction losses in switching applications. The PN3643_D27Z datasheet confirms this parameter in its On Characteristics table.

Is PN3643_D27Z suitable for RF amplifier use, and what gain performance is confirmed?

Yes, PN3643_D27Z is characterized for RF use at 30 MHz, delivering G_pe = 10 dB under V_CE = 15 V, R_G = 140 Ω, and R_L = 260 Ω. Its Cob = 8.0 pF and η = 60% further support narrowband VHF amplification. The PN3643_D27Z datasheet explicitly lists these small-signal parameters in the Electrical Characteristics section.

What is the pin configuration of PN3643_D27Z, and how is it verified?

PN3643_D27Z uses a standard TO-92 package with Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector - confirmed by the "1. Emitter 2. Base 3. Collector" notation in the official Fairchild datasheet Rev. B. This pinout is mechanically and electrically validated per JEDEC TO-92 specifications and matches industry-standard NPN orientation. The PN3643_D27Z pinout is consistent across all documented revisions.

What thermal resistance values apply to PN3643_D27Z, and how do they impact layout?

PN3643_D27Z has R_θJA = 200 °C/W and R_θJC = 83.3 °C/W. These values mean that without added copper pour or airflow, a 625 mW power dissipation raises junction temperature by 125 °C above ambient - exceeding the 150 °C limit. Layout must include ≥ 1 cm² of 2-oz copper connected to the collector lead. The PN3643_D27Z thermal data is sourced from the Absolute Maximum Ratings and Thermal Characteristics sections of the datasheet.

PN3643_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:: 220mV @ 15mA, 150mA

Current - Collector Cutoff (Max):: 50nA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 100 @ 150mA, 10V

Power - Max:: 625 mW

Frequency - Transition:: -

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

PN3643_D27Z FAQ

1.How can I place an order for PN3643_D27Z through Aetrix?

Please submit a Request for Quotation (RFQ) for PN3643_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 PN3643_D27Z reliable?

The price and inventory of PN3643_D27Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for PN3643_D27Z is usually 5 days.

3.What payment methods are accepted for PN3643_D27Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for PN3643_D27Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for PN3643_D27Z?

PN3643_D27Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your PN3643_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 PN3643_D27Z?

For technical support, including PN3643_D27Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your PN3643_D27Z requirements.

6.How does Aetrix verify that PN3643_D27Z is sourced from the original manufacturer or authorized distributors?

All PN3643_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 PN3643_D27Z meets industry standards.

7.What is the process for return or replacement of PN3643_D27Z?

All PN3643_D27Z units undergo pre-shipment inspection (PSI). If there is an issue with PN3643_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 PN3643_D27Z part is unused and in its original packaging.

Return procedure for PN3643_D27Z:

1.Submit a request within 90 days.

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

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