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onsemi NZT651
- Part No.:
- NZT651
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-261-4, TO-261AA
- Datasheet:
-
NZT651.pdf
- Description:
- TRANS NPN 60V 4A SOT-223-4
- Quantity:
- Payment:
- Shipping:
Inventory:2,966
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Product details
Overview
NZT651 from ON Semiconductor is an NPN current driver transistor in SOT-223-4L package, rated for 60 V VCEO, 4.0 A continuous collector current, and 1.2 W power dissipation at 25°C. It delivers hFE ≥ 75 at IC = 50–1000 mA, VCE = 2.0 V, with VCE(sat) = 0.3 V at IC = 1.0 A / IB = 100 mA - optimized for high-current switching in DC-DC regulators and linear power amplifiers.
For engineers reviewing the NZT651 datasheet, pinout, applications, or equivalent options, key selection criteria include its 75 MHz fT, low saturation voltage under high drive, thermal resistance of 103°C/W on FR-4, and compatibility with SOT-223 footprint layouts requiring robust current-handling capability in compact power stages.
Technical Context
The NZT651 is a silicon planar epitaxial NPN transistor fabricated in Fairchild's Process 4P, designed specifically for medium-power switching and linear amplification where speed and saturation performance are critical. Its fT of 75 MHz at IC = 50 mA confirms RF-capable gain-bandwidth behavior, while VCE(sat) remains ≤ 0.5 V up to 2.0 A with appropriate base drive.
Thermal design relies on the exposed collector tab (Pin 2 & 4) soldered to ≥6 cm² copper area on FR-4, enabling 1.2 W dissipation at 25°C ambient. Absolute maximum ratings specify 150°C junction temperature, -55°C to +150°C operating range, and 80 V VCBO - supporting use in boost converters and motor drivers with transient voltage margin.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 60 V - supports operation in 48 V bus systems with safety margin against inductive kickback |
| IC (continuous) | 4.0 A - enables direct drive of solenoids, LED arrays, or MOSFET gates without external buffering |
| VCE(sat) | 0.3 V @ 1.0 A/100 mA - minimizes conduction loss and self-heating in high-duty-cycle switching |
| fT | 75 MHz - ensures stable gain in audio preamps and fast-switching PWM control loops |
| RθJA | 103 °C/W - requires ≥6 cm² PCB copper pour for thermal compliance at full load |
| hFE | 75 @ 50–1000 mA - provides predictable current amplification across wide load range without gain collapse |
| PD | 1.2 W @ 25°C - defines maximum steady-state power handling before thermal derating begins |
Pinout & Package
SOT-223-4L package with thermally enhanced lead frame: Pin 1 = Base, Pins 2 & 4 = Collector (internally connected, exposed tab), Pin 3 = Emitter. The dual-collector configuration improves thermal transfer and current capacity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Base | Control input requiring ~100 mA drive for full 1.0 A output; low VBE(sat) = 1.2 V reduces driver stage burden |
| Pins 2 & 4 | Collector | Internally shorted high-current terminals; must be soldered to large copper area for thermal management |
| Pin 3 | Emitter | Power return path; referenced to system ground in low-side switch configurations |
Key Features
| Feature | Design Value |
|---|---|
| High-current NPN topology | 4.0 A IC rating enables replacement of discrete Darlington pairs in space-constrained designs |
| Low VCE(sat) | 0.3 V at 1.0 A reduces power loss by >50% vs. standard general-purpose transistors at same current |
| 75 MHz fT | Supports clean square-wave switching up to ~10 MHz with minimal rise/fall time degradation |
| SOT-223 thermal design | Exposed collector tab allows 1.2 W dissipation on standard FR-4 - no heatsink required below 1 W |
| Wide temperature range | -55°C to +150°C operation supports automotive under-hood and industrial motor control environments |
Applications
| DC-DC Regulator Switch | Linear Power Amplifier |
|---|---|
Use Scenario: High-efficiency buck converter output stage driving 2–3 A loads at 12–48 V input. IC Role / Device Role / Timing Role: Main power switch controlling energy transfer to output inductor; operated in saturated switching mode. Use Value: Low VCE(sat) and high hFE reduce conduction loss and gate-drive complexity versus MOSFET alternatives. |
Use Scenario: Class-A/B audio amplifier output stage delivering 1–2 W into 4–8 Ω speakers. IC Role / Device Role / Timing Role: Linear current source amplifying analog signal with minimal crossover distortion. Use Value: Stable hFE across 50 mA–2 A ensures consistent gain linearity and thermal predictability. |
| Motor Driver Half-Bridge | LED Current Regulator |
Use Scenario: Low-voltage brushed DC motor control (12–24 V) in robotics or HVAC actuators. IC Role / Device Role / Timing Role: Low-side switch in H-bridge configuration, commutated at ≤20 kHz PWM frequency. Use Value: 75 MHz fT and fast saturation support clean PWM edges, minimizing shoot-through risk. |
Use Scenario: Constant-current driver for high-brightness LED strings in signage or industrial lighting. IC Role / Device Role / Timing Role: Precision current sink controlled via feedback resistor network. Use Value: Tight hFE tolerance and low VBE(on) = 1.0 V enable accurate current regulation without trimming. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN current driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ZXTN2012Z | Higher VCEO = 100 V, lower IC = 2.5 A, SOT-89 package - smaller thermal mass, higher RθJA = 150°C/W | Better suited for higher-voltage, lower-current flyback snubbers; less ideal for 4 A continuous loads | Select when board space is constrained and voltage margin >80 V is required over current capacity |
| MJD127G | Same SOT-223-4L package, but PNP complement; VCEO = 100 V, IC = 2.0 A, hFE = 30–120 - wider gain spread, higher VCE(sat) | Used in complementary emitter-follower outputs or high-side switches - not a direct functional substitute | Choose only for PNP-side matching in push-pull topologies; not interchangeable with NZT651 in NPN roles |
Compared with ZXTN2012Z and MJD127G, the NZT651 uniquely balances 4.0 A current capability, 60 V rating, and 0.3 V saturation in SOT-223 - making it optimal for cost-sensitive, thermally constrained NPN switching where both current and voltage headroom matter.
Availability
NZT651 is available at Aetrix Electronics and suitable for DC-DC regulators, motor drivers, LED current regulators, and linear amplifier circuits requiring stable component supply with long-term industrial lifecycle support.
Supply support for NZT651 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
ON Semiconductor (formerly Fairchild Semiconductor) is a global leader in power management, analog, sensor, and connectivity solutions, serving automotive, industrial, cloud, and consumer markets.
The NZT651 belongs to ON Semiconductor's legacy power bipolar transistor portfolio, engineered for high-reliability medium-power switching and amplification in cost-sensitive industrial and automotive subsystems.
FAQ
What is the maximum continuous collector current rating for the NZT651?
The NZT651 is rated for 4.0 A continuous collector current (IC) at TA = 25°C with proper PCB thermal management. Derating applies above 25°C at 9.7 mW/°C, and actual usable current depends on layout - specifically, a minimum 6 cm² copper area connected to the collector tab (Pins 2 & 4) is required to sustain full-rated current without exceeding 150°C junction temperature. The NZT651 datasheet specifies this limit under steady-state conditions with defined FR-4 mounting.
Does the NZT651 have a documented pin-to-pin replacement?
No documented pin-to-pin replacement for the NZT651 is confirmed in official ON Semiconductor documentation. While other SOT-223 NPN transistors like the MJD112 share similar pinout (B-C-E-C), they differ in VCEO, hFE, and saturation characteristics - requiring validation per application. The NZT651's dual-collector construction and specific gain/saturation profile make direct substitution unreliable without circuit-level verification of thermal, gain, and switching behavior.
What is the typical DC current gain (hFE) of the NZT651 across operating current?
The NZT651 exhibits hFE ≥ 75 at IC = 50 mA, 500 mA, and 1.0 A (VCE = 2.0 V), dropping to ≥ 40 at IC = 2.0 A. This flat gain curve up to 1 A simplifies biasing in linear amplifiers and ensures predictable drive requirements in switching applications. The NZT651 maintains usable gain well into high-current regions, unlike many general-purpose transistors that exhibit sharp roll-off beyond 500 mA.
Can the NZT651 be used in high-frequency switching applications?
Yes - the NZT651 has a current gain–bandwidth product (fT) of 75 MHz at IC = 50 mA, VCE = 5.0 V, f = 100 MHz, confirming suitability for switching up to several megahertz. Its low storage time and fast saturation recovery support clean PWM waveforms in DC-DC controllers and motor drives. However, the NZT651 is not optimized for RF power amplification; its primary strength lies in medium-speed, high-current digital and analog power stages.
What is the recommended PCB land pattern for the NZT651 SOT-223 package?
The NZT651 uses JEDEC TO-261C (Variation AA) packaging, with recommended land pattern name SOT230P700X180-4BN. Critical features include a large copper pour (≥6 cm²) connected to Pins 2 & 4 (collector), 1.90 mm pad width for Pin 1 (base), and 3.25 mm spacing between Pin 1 and Pin 3 (emitter). Thermal vias under the collector tab are strongly advised to enhance heat transfer to inner layers. The NZT651 thermal performance degrades significantly if the land pattern deviates from these guidelines.
NZT651 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-261-4, TO-261AA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 4 A
- Voltage - Collector Emitter Breakdown (Max):
- 60 V
- Vce Saturation (Max) @ Ib, Ic:
- 500mV @ 200mA, 2A
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 40 @ 2A, 2V
- Power - Max:
- 1.2 W
- Frequency - Transition:
- 75MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-223-4
NZT651 FAQ
1.How can I place an order for NZT651 through Aetrix?
Please submit a Request for Quotation (RFQ) for NZT651 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 NZT651 reliable?
The price and inventory of NZT651 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for NZT651 is usually 5 days.
3.What payment methods are accepted for NZT651?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for NZT651 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for NZT651?
NZT651 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your NZT651 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 NZT651?
For technical support, including NZT651 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your NZT651 requirements.
6.How does Aetrix verify that NZT651 is sourced from the original manufacturer or authorized distributors?
All NZT651 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 NZT651 meets industry standards.
7.What is the process for return or replacement of NZT651?
All NZT651 units undergo pre-shipment inspection (PSI). If there is an issue with NZT651, 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 NZT651 part is unused and in its original packaging.
Return procedure for NZT651:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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