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

onsemi PN4143

Name: PN4143
Brand: onsemi
SKU: PN4143
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: PN4143

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: PN4143.pdf

Description:: TRANS PNP 40V 0.8A TO-92-3

Quantity:: RFQ Add To RFQ list

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Inventory:8,992

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Product details

Overview

PN4143 from Fairchild Semiconductor is a PNP general-purpose bipolar junction transistor (BJT) designed for amplification and switching applications up to 500 mA collector current. It features a 40 V V_CEO, 60 V V_CBO, 5.0 V V_EBO, 625 mW power dissipation at 25°C, and TO-92 package. It is commonly used in low-voltage DC-DC converter bias circuits and discrete logic-level switching.

For engineers reviewing the PN4143 datasheet, pinout, applications, or equivalent options, key selection considerations include its PNP polarity, 800 mA absolute maximum collector current, 150°C max junction temperature, saturation voltage performance at 150 mA/15 mA drive, and thermal resistance of 200°C/W (junction-to-ambient).

Technical Context

The PN4143 operates as a silicon PNP BJT fabricated on Fairchild's Process 63. Its DC current gain (h_FE) ranges from 35 to 300 depending on collector current - 75 at IC = 10 mA, 100 at IC = 150 mA, and 30 at IC = 500 mA - indicating strong low-current amplification but intentional de-rating at high current for thermal stability.

Switching performance is characterized by 45 ns turn-on time, 10 ns delay, 40 ns rise, 100 ns turn-off, 80 ns storage, and 30 ns fall times under specified 30 V/150 mA pulsed conditions. Small-signal h_fe is 2.0 at 50 mA, 20 V V_CE, and 100 MHz - confirming suitability for low-frequency amplification rather than RF use.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	40 V - Maximum safe collector-emitter voltage before breakdown; defines upper rail limit in switch designs.
I_C (max)	800 mA - Absolute continuous collector current rating; usable up to 500 mA per design intent.
P_D	625 mW at 25°C - Total power dissipation limit; derates 5.0 mW/°C above ambient.
R_θJA	200 °C/W - Junction-to-ambient thermal resistance; requires heatsinking or board copper for >200 mW sustained operation.
h_FE @ IC=150 mA	100 - DC current gain at mid-range switching current; enables ~15 mA base drive for 150 mA collector load.
V_CE(sat) @ IC=150 mA	0.4 V - Low saturation voltage ensures <60 mW collector loss at 150 mA, minimizing heat generation.
f_T	Not specified - No transition frequency given; device not intended for RF or high-speed analog amplification.

Pinout & Package

PN4143 is supplied in a standard through-hole TO-92 plastic package with straight leads and no lead clip. Pin identification follows JEDEC TO-92 outline: when flat side faces user and leads point downward, left-to-right pin order is Emitter (E), Base (B), Collector (C).

Pin/Terminal	Circuit Role	Design Meaning
Emitter (E)	Current exit terminal for PNP device	Connected to higher potential (e.g., V_CC) in common-emitter switch configurations.
Base (B)	Control terminal for minority-carrier injection	Receives forward-biased current to enable conduction; typical drive ~10–20 mA for full saturation.
Collector (C)	Current entry terminal for PNP device	Connected to load and ground-side return path; carries full switched load current.

Key Features

Feature	Design Value
High V_CBO rating	60 V - Enables robust operation in inductive load switching where collector voltage spikes may exceed supply rail.
Low V_CE(sat)	0.4 V at 150 mA - Reduces conduction loss and self-heating in linear regulator pass elements or power switches.
Wide operating temperature	−55°C to +150°C - Supports industrial and automotive under-hood environments without derating.
Controlled h_FE spread	Min 35 / Max 300 - Ensures predictable base drive requirements across production lots for reliable switching threshold design.
TO-92 mechanical standardization	JEDEC registered outline - Guarantees compatibility with automated insertion equipment and legacy PCB footprints.

Applications

LED Driver Circuit	DC-DC Converter Bias
Use Scenario: Driving high-brightness indicator LEDs from microcontroller GPIO pins with current limiting. IC Role / Device Role / Timing Role: PNP switch controlling LED anode connection to V_CC; base driven by active-low MCU output. Use Value: 0.4 V V_CE(sat) preserves >3.0 V across LED at 20 mA, enabling full brightness with minimal voltage headroom.	Use Scenario: Providing startup current to PWM controller ICs in offline flyback converters before auxiliary winding becomes active. IC Role / Device Role / Timing Role: High-voltage PNP pass element delivering initial bias current from rectified AC line to controller V_DD. Use Value: 60 V V_CBO withstands peak rectified line voltage (e.g., 375 VDC), while 150°C rating supports enclosed transformer environments.
Discrete Logic Inverter	Relay Driver Interface
Use Scenario: Converting TTL/CMOS logic levels to inverted open-collector outputs for interfacing with legacy 5 V systems. IC Role / Device Role / Timing Role: Common-emitter amplifier configured as saturated switch with pull-up resistor on collector. Use Value: 100 h_FE at 10 mA ensures clean logic transitions with <1 µs propagation delay in buffered configurations.	Use Scenario: Isolating and amplifying low-power control signals to energize 12 V/24 V electromagnetic relays in PLC I/O modules. IC Role / Device Role / Timing Role: Medium-current PNP driver stage sinking relay coil current from positive rail to ground-return path. Use Value: 500 mA rated collector current supports 400 mA relay coils with 25% margin; 80 ns storage time minimizes relay release delay.

LED Driver Circuit

DC-DC Converter Bias

Use Scenario: Driving high-brightness indicator LEDs from microcontroller GPIO pins with current limiting.

IC Role / Device Role / Timing Role: PNP switch controlling LED anode connection to V_CC; base driven by active-low MCU output.

Use Value: 0.4 V V_CE(sat) preserves >3.0 V across LED at 20 mA, enabling full brightness with minimal voltage headroom.

Use Scenario: Providing startup current to PWM controller ICs in offline flyback converters before auxiliary winding becomes active.

IC Role / Device Role / Timing Role: High-voltage PNP pass element delivering initial bias current from rectified AC line to controller V_DD.

Use Value: 60 V V_CBO withstands peak rectified line voltage (e.g., 375 VDC), while 150°C rating supports enclosed transformer environments.

Discrete Logic Inverter

Relay Driver Interface

Use Scenario: Converting TTL/CMOS logic levels to inverted open-collector outputs for interfacing with legacy 5 V systems.

IC Role / Device Role / Timing Role: Common-emitter amplifier configured as saturated switch with pull-up resistor on collector.

Use Value: 100 h_FE at 10 mA ensures clean logic transitions with <1 µs propagation delay in buffered configurations.

Use Scenario: Isolating and amplifying low-power control signals to energize 12 V/24 V electromagnetic relays in PLC I/O modules.

IC Role / Device Role / Timing Role: Medium-current PNP driver stage sinking relay coil current from positive rail to ground-return path.

Use Value: 500 mA rated collector current supports 400 mA relay coils with 25% margin; 80 ns storage time minimizes relay release delay.

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	Higher V_CEO (300 V), lower h_FE (25–100), TO-92 package	Better suited for high-voltage AC line sensing; less ideal for low-V_CE saturation-critical loads	Select when >100 V collector swing is required; avoid if V_CE(sat) < 0.5 V is mandatory.
BC557	Lower I_C (100 mA), tighter h_FE binning (110–800), same TO-92	Optimized for signal amplification, not power switching; insufficient for >200 mA loads	Prefer for audio preamp or sensor interface; not recommended for 500 mA switching duty.

Compared with MPSA92 and BC557, PN4143 uniquely balances 40 V breakdown, 500 mA switching capability, and 0.4 V saturation voltage - making it optimal for medium-current, medium-voltage discrete power control where thermal margin and conduction loss are both critical.

Availability

PN4143 is available at Aetrix Electronics and suitable for LED driver circuits, DC-DC converter bias networks, and discrete logic inverters requiring stable component supply and long-term industrial availability.

Supply support for PN4143 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.

PN4143 belongs to Fairchild's general-purpose bipolar transistor family designed for cost-sensitive, medium-current amplification and switching in industrial controls, power supplies, and legacy interface circuits.

FAQ

What is the maximum continuous collector current for PN4143?

The PN4143 has an absolute maximum continuous collector current (I_C) rating of 800 mA per its datasheet. However, the device is specifically characterized and recommended for use up to 500 mA in general-purpose amplifier and switching applications, balancing thermal performance and reliability under sustained operation.

Is PN4143 pin-compatible with PN2907A?

Yes, PN4143 shares identical pinout, package (TO-92), and electrical specifications with PN2907A, as confirmed by Fairchild's cross-reference note stating "See PN2907A for characteristics." Both devices exhibit matching V_CEO, h_FE, and saturation voltage behavior under equivalent test conditions.

What is the thermal resistance junction-to-ambient for PN4143?

The PN4143 has a specified R_θJA of 200°C/W at T_A = 25°C. This value assumes standard PCB mounting on FR-4 with minimal copper area; actual thermal performance improves significantly with added copper pour or thermal vias beneath the collector pad.

Does PN4143 support high-frequency signal amplification?

No, PN4143 is not intended for high-frequency amplification. Its small-signal current gain h_fe is specified only at 100 MHz (value = 2.0), and no transition frequency (f_T) is provided. The device is optimized for DC and low-frequency switching (<1 MHz), not RF or broadband analog applications.

What is the emitter-base breakdown voltage of PN4143?

The PN4143 has a guaranteed minimum V_(BR)EBO of 5.0 V at I_E = 10 µA, meaning the emitter-base junction will not break down below this voltage under reverse bias - critical for ensuring safe operation in circuits with negative transients or level-shifting configurations.

PN4143 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

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

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 800 mA

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

Vce Saturation (Max) @ Ib, Ic:: 1.6V @ 50mA, 500mA

Current - Collector Cutoff (Max):: -

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

PN4143 FAQ

1.How can I place an order for PN4143 through Aetrix?

Please submit a Request for Quotation (RFQ) for PN4143 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 PN4143 reliable?

The price and inventory of PN4143 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for PN4143 is usually 5 days.

3.What payment methods are accepted for PN4143?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for PN4143 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for PN4143?

PN4143 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your PN4143 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 PN4143?

For technical support, including PN4143 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your PN4143 requirements.

6.How does Aetrix verify that PN4143 is sourced from the original manufacturer or authorized distributors?

All PN4143 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 PN4143 meets industry standards.

7.What is the process for return or replacement of PN4143?

All PN4143 units undergo pre-shipment inspection (PSI). If there is an issue with PN4143, 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 PN4143 part is unused and in its original packaging.

Return procedure for PN4143:

1.Submit a request within 90 days.

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

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