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onsemi FJX2222ATF
- Part No.:
- FJX2222ATF
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- SC-70, SOT-323
- Datasheet:
-
FJX2222ATF.pdf
- Description:
- TRANS NPN 40V 0.6A SOT-323
- Quantity:
- Payment:
- Shipping:
Inventory:3,638
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Product details
Overview
FJX2222ATF from ON Semiconductor is a general-purpose NPN epitaxial silicon transistor in SC-70 (SOT-323) package, rated for 40 V VCEO, 600 mA IC, and 325 mW PD. It delivers DC current gain (hFE) of 75–300 at IC = 10–150 mA and supports high-speed switching with 300 MHz fT, commonly used in low-power amplification and digital switching circuits.
For engineers reviewing the FJX2222ATF datasheet, pinout, applications, or equivalent options, key selection criteria include its SC-70 footprint compatibility, VCEO/IC derating behavior above 25°C, saturation voltage performance at defined drive conditions, and thermal resistance (RθJA = 385°C/W) for board-level thermal design.
Technical Context
The FJX2222ATF operates as a discrete bipolar junction transistor with fixed NPN polarity, optimized for linear amplification and saturated-switching modes. Its hFE spans 35–300 across IC = 0.1–500 mA, and it exhibits VCE(sat) ≤ 0.3 V at IC = 150 mA / IB = 15 mA - confirming suitability for low-loss switching in portable logic interfaces.
It features fT = 300 MHz at IC = 20 mA / VCE = 20 V, Cob = 8 pF at VCB = 10 V, and tON/tOFF = 35 ns / 285 ns under specified test conditions - indicating bandwidth-limited but predictable dynamic response for sub-MHz signal routing and pulse generation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 40 V - Maximum collector-emitter voltage before breakdown; defines safe operating range in common-emitter switch/amplifier configurations. |
| IC | 600 mA - Continuous collector current rating; sets upper limit for load-driving capability without thermal runaway at TA ≤ 25°C. |
| PD | 325 mW - Maximum power dissipation at 25°C ambient; requires derating by 2.6 mW/°C above this temperature for thermal safety. |
| hFE | 75–300 - DC current gain at VCE = 10 V; enables precise base-current sizing for bias stability across production lots. |
| fT | 300 MHz - Current gain bandwidth product; confirms usable small-signal amplification up to ~100 MHz with proper impedance matching. |
| RθJA | 385°C/W - Junction-to-ambient thermal resistance; determines temperature rise per watt dissipated on standard FR-4 PCB with minimum land pattern. |
Pinout & Package
Package: SC-70 (SOT-323), 3-lead surface-mount plastic package with 1.25 mm body width, optimized for space-constrained PCB layouts and automated assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base | Control terminal for forward-biasing the BE junction; requires current-limited drive to achieve target IC and avoid saturation delay. |
| 2 | Emitter | Current return path; connected to ground or low-impedance reference in common-emitter configuration; influences VBE(sat) and thermal coupling. |
| 3 | Collector | Output current sink; handles full load current and must be routed with adequate copper area to manage power dissipation and minimize inductive kick. |
Key Features
| Feature | Design Value |
|---|---|
| General-purpose NPN architecture | Enables drop-in replacement in legacy 2N2222A-based designs while maintaining SOT-323 footprint and thermal profile. |
| VCEO = 40 V with VCBO = 75 V | Provides 1.88× overvoltage margin for transient suppression in 24 V industrial control inputs and relay drivers. |
| VCE(sat) ≤ 0.3 V @ IC/IB = 150 mA/15 mA | Reduces conduction loss to < 45 mW in saturated switching, improving efficiency in battery-powered LED/motor drivers. |
| fT = 300 MHz | Supports clean square-wave propagation up to ~30 MHz with minimal rise/fall time degradation in clock buffering applications. |
| SC-70 package with 0.65 mm pitch | Enables high-density placement in wearables and IoT sensor nodes where board area is constrained to < 5 mm² per transistor. |
Applications
| Low-Voltage Switching | Small-Signal Amplification |
|---|---|
Use Scenario: Driving 5 V logic-level relays and optocouplers in programmable logic controllers. IC Role / Device Role / Timing Role: Discrete NPN switch controlling coil current with fast turn-on (35 ns) and controlled saturation. Use Value: Low VCE(sat) minimizes heat generation during continuous duty cycles, extending relay lifetime in industrial automation. |
Use Scenario: Pre-amplifying microphone signals in portable audio recorders. IC Role / Device Role / Timing Role: Single-stage common-emitter amplifier with hFE ≥ 75 at IC = 100 μA–1 mA for gain stability. Use Value: NF = 4 dB at 1 kHz ensures minimal added noise in front-end analog chains before ADC sampling. |
| Digital Logic Interface | LED Driver Circuit |
Use Scenario: Level-shifting between 3.3 V microcontroller GPIO and 5 V peripheral buses. IC Role / Device Role / Timing Role: Inverting buffer with sharp edge transition enabled by 300 MHz fT and low Cob (8 pF). Use Value: Predictable tON/tOFF allows reliable timing margins in 1–5 MHz data strobes without external compensation. |
Use Scenario: Constant-current sinking for indicator LEDs in medical handheld devices. IC Role / Device Role / Timing Role: Linear-mode current regulator using emitter resistor feedback and stable hFE variation. Use Value: Tight VBE(sat) tolerance (0.6–1.2 V) ensures consistent LED brightness across temperature and unit-to-unit variance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN general-purpose transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMBT2222ALT1G | VCEO = 40 V, IC = 600 mA, but hFE min = 100 @ IC = 150 mA - tighter gain distribution than FJX2222ATF's 75–300 range. | Preferred in precision bias networks requiring predictable current mirroring; less suitable for wide-gain-tolerance switching. | Select when hFE consistency > 20% variation is required across temperature and process corners. |
| PN2222A | TO-92 through-hole package; identical electrical specs but RθJA ≈ 200°C/W - significantly better thermal performance than SC-70's 385°C/W. | Used in prototyping, repair, and low-volume assemblies where manual soldering and thermal headroom are priorities. | Choose for bench testing or cost-sensitive non-SMT applications where board space is not constrained. |
Compared with MMBT2222ALT1G and PN2222A, the FJX2222ATF offers optimal balance of SC-70 miniaturization, moderate gain spread, and proven reliability in high-volume consumer electronics - making it ideal for space-limited production designs requiring validated thermal derating curves.
Availability
FJX2222ATF is available at Aetrix Electronics and suitable for low-power switching, small-signal amplification, and digital interface applications requiring stable component supply, consistent parametric binning, and long-term manufacturing continuity.
Supply support for FJX2222ATF 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 is a global semiconductor manufacturer specializing in energy-efficient power management, analog, sensors, and discrete components for automotive, industrial, cloud, and IoT systems.
The FJX2222ATF belongs to ON Semiconductor's legacy Fairchild discrete transistor portfolio, designed specifically for cost-sensitive, high-reliability general-purpose switching and amplification in consumer and industrial electronics.
FAQ
What is the maximum operating temperature for the FJX2222ATF?
The FJX2222ATF has a maximum junction temperature (TJ) of 150°C and storage temperature (TSTG) of –65°C to +150°C. Its thermal resistance RθJA is 385°C/W on a standard FR-4 PCB, meaning sustained power dissipation must be limited to maintain TJ below 150°C. Derating begins at 25°C ambient, reducing allowable PD by 2.6 mW per °C rise.
Does the FJX2222ATF support high-frequency signal amplification?
Yes, the FJX2222ATF has a current gain bandwidth product (fT) of 300 MHz at IC = 20 mA and VCE = 20 V, enabling usable small-signal amplification up to approximately 100 MHz with appropriate biasing and impedance matching. Its Cob = 8 pF at VCB = 10 V further supports stable RF performance in narrowband front-end stages.
What is the typical VCE(sat) of the FJX2222ATF under switching conditions?
The FJX2222ATF achieves VCE(sat) ≤ 0.3 V at IC = 150 mA and IB = 15 mA, and ≤ 1.0 V at IC = 500 mA and IB = 50 mA. These values reflect guaranteed saturation performance under pulsed test conditions (≤300 μs, ≤2% duty cycle), ensuring low conduction loss in digital switching applications.
Is the FJX2222ATF pin-compatible with the classic 2N2222A?
No - the FJX2222ATF uses an SC-70 (SOT-323) surface-mount package with pinout Base–Emitter–Collector (1–2–3), whereas the through-hole 2N2222A uses TO-18 or TO-92 packages with different pin assignments and mechanical dimensions. Direct PCB replacement is not possible without layout revision.
How does the hFE of the FJX2222ATF vary with collector current?
The FJX2222ATF exhibits hFE = 35 at IC = 0.1 mA, rising to 50 at 1 mA, 75–300 at 10–150 mA, and dropping to 40 at 500 mA. This non-monotonic behavior reflects optimized doping profiles for mid-range current operation, requiring careful base-drive design to maintain linearity in amplification or predictable saturation in switching.
FJX2222ATF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- SC-70, SOT-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 600 mA
- Voltage - Collector Emitter Breakdown (Max):
- 40 V
- Vce Saturation (Max) @ Ib, Ic:
- 1V @ 50mA, 500mA
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 100 @ 150mA, 10V
- Power - Max:
- 325 mW
- Frequency - Transition:
- 300MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-323
FJX2222ATF FAQ
1.How can I place an order for FJX2222ATF through Aetrix?
Please submit a Request for Quotation (RFQ) for FJX2222ATF 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 FJX2222ATF reliable?
The price and inventory of FJX2222ATF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FJX2222ATF is usually 5 days.
3.What payment methods are accepted for FJX2222ATF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FJX2222ATF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FJX2222ATF?
FJX2222ATF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FJX2222ATF 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 FJX2222ATF?
For technical support, including FJX2222ATF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FJX2222ATF requirements.
6.How does Aetrix verify that FJX2222ATF is sourced from the original manufacturer or authorized distributors?
All FJX2222ATF 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 FJX2222ATF meets industry standards.
7.What is the process for return or replacement of FJX2222ATF?
All FJX2222ATF units undergo pre-shipment inspection (PSI). If there is an issue with FJX2222ATF, 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 FJX2222ATF part is unused and in its original packaging.
Return procedure for FJX2222ATF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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