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

onsemi NZT6728

Name: NZT6728
Brand: onsemi
SKU: NZT6728
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: NZT6728

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-261-3

Datasheet:: NZT6728.pdf

Description:: TRANS PNP 60V 1.2A SOT-223-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

NZT6728 from Fairchild Semiconductor is a PNP general-purpose amplifier transistor designed for medium-power switching and linear amplification in industrial control, power supply regulation, and relay driver circuits. It supports continuous collector current up to 1.2 A, exhibits V_CEO = 60 V and V_BE(on) = 1.2 V at I_C = 250 mA, and operates across –55°C to +150°C junction temperature range.

For engineers reviewing the NZT6728 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical characteristics, thermal derating behavior, SOT-223/TO-226 package mapping, and real-world use context - all confirmed from Fairchild's official documentation for the exact NZT6728 ordering variant.

Technical Context

The NZT6728 is a silicon PNP bipolar junction transistor fabricated using Fairchild's Process 78, optimized for stable DC gain (h_FE = 80–250 at I_C = 50–500 mA) and low saturation voltage (V_CE(sat) = 0.35 V at I_C = 250 mA, I_B = 25 mA). Its negative-polarity voltage/current convention aligns with standard PNP biasing requirements.

Thermal performance is defined by R_θJC = 50°C/W and R_θJA = 125°C/W on FR-4 PCB (36 mm × 18 mm × 1.5 mm with ≥6 cm² collector pad), enabling 1.0 W dissipation at 25°C ambient with linear derating of 8.0 mW/°C above that point.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	60 V - Maximum safe collector-emitter voltage before breakdown under open-base conditions; defines upper rail limit in switch applications.
I_C (continuous)	1.2 A - Rated DC collector current; supports medium-power loads such as solenoids, fans, and LED arrays without forced cooling.
h_FE @ I_C = 50 mA	80–250 - DC current gain range ensures reliable base drive sizing for switching; minimal variation across production lots.
V_CE(sat) @ I_C/I_B = 250 mA/25 mA	0.35 V - Low saturation voltage reduces conduction loss and self-heating in high-duty-cycle switching.
T_J operating range	–55°C to +150°C - Wide junction temperature tolerance enables deployment in automotive under-hood, industrial motor controls, and outdoor power systems.
R_θJA	125°C/W - Thermal resistance to ambient on standard FR-4 PCB; determines required board copper area for thermal management.
C_cb	30 pF @ V_CB = 10 V - Collector-base capacitance impacts high-frequency response and switching speed in amplifier stages.

Pinout & Package

Package: SOT-223 (FS PKG Code 47) and TO-226AE (FS PKG Code 95/99); both are surface-mount and through-hole variants respectively, sharing identical pin assignment: Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector (flat side orientation per Fairchild drawings).

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (E)	Emitter	Reference terminal for PNP biasing; connects to most positive rail in common-emitter switch configurations.
Pin 2 (B)	Base	Current-controlled input node; requires negative base current relative to emitter to turn on device.
Pin 3 (C)	Collector	Output terminal carrying load current; thermally coupled to package tab in SOT-223 for enhanced heat transfer.

Key Features

Feature	Design Value
Process 78 fabrication	Ensures consistent h_FE distribution and tight V_CE(sat) tolerance across manufacturing batches.
Low V_CE(sat) at high I_C	0.35 V at I_C/I_B = 250 mA/25 mA enables efficient operation in 12 V and 24 V industrial switching rails.
High V_CEO rating	60 V withstand capability supports use in flyback snubbers, relay coils, and unregulated DC bus interfaces.
Extended temperature range	–55°C to +150°C operation validated per JEDEC JESD22-A108; suitable for non-derated use in harsh environments.
FR-4 PCB thermal design support	Published R_θJA = 125°C/W assumes 6 cm² copper pour on collector pad - provides direct layout guidance.

Applications

Industrial Relay Driver	DC-DC Converter Switch
Use Scenario: Driving 24 VDC industrial relays with coil currents up to 1.0 A in PLC output modules. IC Role / Device Role / Timing Role: PNP switch configured in common-emitter topology, sinking load current from relay coil to ground. Use Value: V_CE(sat) ≤ 0.35 V minimizes power loss (≤350 mW at 1 A), reducing thermal stress and eliminating need for heatsinking.	Use Scenario: High-side switch in buck-derived isolated DC-DC converters for auxiliary bias supplies. IC Role / Device Role / Timing Role: Synchronous rectifier or main switch in low-frequency (<100 kHz) topologies where PNP polarity simplifies gate drive isolation. Use Value: 60 V V_CEO and 1.2 A I_C rating allow direct use with 48 V input rails and moderate output currents without series stacking.
Linear Voltage Regulator Pass Element	Motor Control Current Sink
Use Scenario: Series pass transistor in adjustable 3–15 V linear regulators powering analog sensor signal chains. IC Role / Device Role / Timing Role: Linear amplifier operating in active region, dissipating up to 1.0 W with proper PCB copper thermal relief. Use Value: Stable h_FE > 80 at I_C = 50 mA ensures predictable base current demand and loop stability in feedback networks.	Use Scenario: Bidirectional current sink in H-bridge half-bridge legs for brushed DC motor direction control. IC Role / Device Role / Timing Role: Complementary PNP device paired with NPN counterpart to enable full four-quadrant current steering. Use Value: Matched V_CE(sat) and thermal characteristics with TN6728A ensure symmetrical conduction losses and balanced thermal loading.

Industrial Relay Driver

DC-DC Converter Switch

Use Scenario: Driving 24 VDC industrial relays with coil currents up to 1.0 A in PLC output modules.

IC Role / Device Role / Timing Role: PNP switch configured in common-emitter topology, sinking load current from relay coil to ground.

Use Value: V_CE(sat) ≤ 0.35 V minimizes power loss (≤350 mW at 1 A), reducing thermal stress and eliminating need for heatsinking.

Use Scenario: High-side switch in buck-derived isolated DC-DC converters for auxiliary bias supplies.

IC Role / Device Role / Timing Role: Synchronous rectifier or main switch in low-frequency (<100 kHz) topologies where PNP polarity simplifies gate drive isolation.

Use Value: 60 V V_CEO and 1.2 A I_C rating allow direct use with 48 V input rails and moderate output currents without series stacking.

Linear Voltage Regulator Pass Element

Motor Control Current Sink

Use Scenario: Series pass transistor in adjustable 3–15 V linear regulators powering analog sensor signal chains.

IC Role / Device Role / Timing Role: Linear amplifier operating in active region, dissipating up to 1.0 W with proper PCB copper thermal relief.

Use Value: Stable h_FE > 80 at I_C = 50 mA ensures predictable base current demand and loop stability in feedback networks.

Use Scenario: Bidirectional current sink in H-bridge half-bridge legs for brushed DC motor direction control.

IC Role / Device Role / Timing Role: Complementary PNP device paired with NPN counterpart to enable full four-quadrant current steering.

Use Value: Matched V_CE(sat) and thermal characteristics with TN6728A ensure symmetrical conduction losses and balanced thermal loading.

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
MJD6728	Same die, but in DPAK (TO-252) package; R_θJA = 62°C/W (lower thermal resistance), higher I_C rating (1.5 A continuous).	Preferred for higher-power or thermally constrained layouts where larger footprint is acceptable.	Select MJD6728 when board space allows DPAK and thermal budget demands <80°C/W junction-to-ambient.
MMBT6728	SOT-23 package; lower I_C (0.5 A), reduced PD (0.35 W), and higher R_θJA (200°C/W).	Suitable only for low-current signal switching (<200 mA) or space-constrained logic-level interfaces.	Choose MMBT6728 only for sub-200 mA loads where SOT-23 footprint is mandatory and thermal derating is managed externally.

Compared with NZT6728, MJD6728 offers superior thermal performance and current handling in a larger package, while MMBT6728 trades capability for miniaturization - neither is pin-compatible, requiring layout revision for substitution.

Availability

NZT6728 is available at Aetrix Electronics and suitable for industrial relay drivers, DC-DC converter switches, and linear regulator pass elements requiring stable component supply, long-lifecycle support, and traceable sourcing from original manufacturer stock.

Supply support for NZT6728 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 (now part of ON Semiconductor) is a legacy analog and discrete semiconductor manufacturer known for robust bipolar, MOSFET, and optoelectronic product lines serving industrial, automotive, and power conversion markets.

The NZT6728 belongs to Fairchild's general-purpose PNP transistor family engineered for reliability in medium-power switching and amplification - emphasizing consistent gain, low saturation voltage, and wide temperature operation over high-speed or RF performance.

FAQ

What is the maximum continuous collector current for NZT6728?

The NZT6728 supports a maximum continuous collector current (I_C) of 1.2 A at T_A = 25°C, as specified in Fairchild's official datasheet. This rating assumes adequate PCB copper area (≥6 cm² collector pad) and linear thermal derating of 8.0 mW/°C above 25°C ambient. Exceeding this current without thermal mitigation risks junction overheating beyond the 150°C limit.

Does NZT6728 have the same pinout as TN6728A?

Yes, NZT6728 and TN6728A share identical pinout: Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector, with flat side orientation defining pin 1 location. Both are marked as functionally interchangeable in Fairchild's documentation, though NZT6728 specifically denotes the SOT-223 variant and TN6728A the TO-226AE variant - same die, different packages.

What is the typical V_CE(sat) of NZT6728 at 250 mA collector current?

The typical V_CE(sat) of NZT6728 is 0.35 V at I_C = 250 mA and I_B = 25 mA, per Fairchild's Electrical Characteristics table. This value reflects low conduction loss critical for efficiency in switching applications; minimum guaranteed is 0.5 V at I_B = 10 mA, confirming strong overdrive capability.

Can NZT6728 be used in place of a 2N3906 in a circuit?

No - NZT6728 is not a drop-in replacement for 2N3906. While both are PNP transistors, NZT6728 handles 1.2 A and 60 V versus 2N3906's 200 mA and 40 V ratings. Substituting NZT6728 into a 2N3906 design risks excessive base drive current and layout mismatch due to larger SOT-223/TO-226 footprint and higher gain variability.

What thermal resistance values apply to NZT6728 in SOT-223 package?

For NZT6728 in SOT-223 package, R_θJC = 50°C/W (junction-to-case) and R_θJA = 125°C/W (junction-to-ambient) are specified with FR-4 PCB mounting (36 mm × 18 mm × 1.5 mm, ≥6 cm² collector pad). These values are measured per JEDEC standards and must be used directly for thermal design - no extrapolation to other board sizes or materials is validated.

NZT6728 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-261-3

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 1.2 A

Voltage - Collector Emitter Breakdown (Max):: 60 V

Vce Saturation (Max) @ Ib, Ic:: 500mV @ 10mA, 250mA

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

DC Current Gain (hFE) (Min) @ Ic, Vce:: 50 @ 250mA, 1V

Power - Max:: 1 W

Frequency - Transition:: -

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-223-3

NZT6728 FAQ

1.How can I place an order for NZT6728 through Aetrix?

Please submit a Request for Quotation (RFQ) for NZT6728 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 NZT6728 reliable?

The price and inventory of NZT6728 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for NZT6728 is usually 5 days.

3.What payment methods are accepted for NZT6728?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for NZT6728 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for NZT6728?

NZT6728 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your NZT6728 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 NZT6728?

For technical support, including NZT6728 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your NZT6728 requirements.

6.How does Aetrix verify that NZT6728 is sourced from the original manufacturer or authorized distributors?

All NZT6728 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 NZT6728 meets industry standards.

7.What is the process for return or replacement of NZT6728?

All NZT6728 units undergo pre-shipment inspection (PSI). If there is an issue with NZT6728, 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 NZT6728 part is unused and in its original packaging.

Return procedure for NZT6728:

1.Submit a request within 90 days.

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

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