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onsemi FJN3301RTA
- Part No.:
- FJN3301RTA
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
FJN3301RTA.pdf
- Description:
- TRANS NPN 50V 0.1A TO-92-3
- Quantity:
- Payment:
- Shipping:
Inventory:47,639
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Product details
Overview
FJN3301RTA from Fairchild Semiconductor is an NPN epitaxial silicon transistor with integrated bias resistors (R1 = R2 = 4.7 kΩ), designed for digital switching and interface applications. It supports 100 mA collector current, 50 V VCEO and VCBO ratings, and operates up to 150°C junction temperature - commonly used in industrial logic-level drivers and signal inversion circuits.
For engineers reviewing the FJN3301RTA datasheet, pinout, applications, or equivalent options, key selection criteria include input-on/off voltage thresholds (VI(on) = 3 V, VI(off) = 0.5 V), hFE ≥ 20 at IC = 10 mA, saturation voltage of 0.3 V, and TO-92 package compatibility with through-hole PCB layouts.
Technical Context
This device integrates two matched 4.7 kΩ bias resistors (R1 from base to VIN, R2 from base to emitter) to form a single-transistor digital switch with defined turn-on/turn-off thresholds. Its 250 MHz fT and low Cob (3.7 pF) support reliable high-speed digital switching up to several MHz in buffered gate drive and level-shifting roles.
The FJN3301RTA uses an epitaxial base structure for stable hFE across temperature and exhibits tight resistor ratio control (R1/R2 = 0.9–1.1), enabling consistent logic threshold behavior without external component tuning. Its 300 mW power dissipation and 416°C/W thermal resistance are specified under standard FR-4 PCB conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO / VCBO | 50 V - Supports rail-to-rail switching in 24 V industrial control and 3.3/5 V logic interfaces without breakdown risk. |
| IC(max) | 100 mA - Sufficient to directly drive LEDs, small relays, or MOSFET gates in low-power digital systems. |
| hFE | ≥20 at VCE = 5 V, IC = 10 mA - Ensures reliable saturation with modest base drive, reducing MCU GPIO loading. |
| VCE(sat) | 0.3 V at IC = 10 mA, IB = 0.5 mA - Minimizes conduction loss and self-heating in continuous switching operation. |
| R1 / R2 | 4.7 kΩ ±30% - Enables direct connection to 3.3 V or 5 V logic outputs without external bias network. |
| fT | 250 MHz - Allows clean edge response in pulse-width modulation and clock buffering up to ~10 MHz. |
| VI(on) / VI(off) | 3.0 V / 0.5 V - Provides noise-immune TTL/CMOS-compatible switching with >2.5 V hysteresis margin. |
Pinout & Package
Package: TO-92 3L molded plastic case with straight or bent leads; standard through-hole mounting footprint per JEDEC TO-92 outline.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Current sink terminal | Connected internally to R2; provides reference node for bias network and output return path. |
| 2 (Collector) | Switched output terminal | High-side load connection point; carries full switched current up to 100 mA. |
| 3 (Base) | Input node between R1 and R2 | Internal junction of built-in resistors - no external base connection required for basic switching. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated dual-bias resistor network | Eliminates two external resistors, reducing BOM count and PCB area in discrete logic interface designs. |
| Matched R1/R2 ratio | 0.9–1.1 tolerance ensures predictable VI(on)/VI(off) thresholds across production lots. |
| Low VCE(sat) | 0.3 V enables <10 mW conduction loss at 10 mA, supporting thermally constrained enclosures. |
| High fT bandwidth | 250 MHz allows use in pulse shaping, clock division, and fast edge regeneration without added ICs. |
| TO-92 mechanical compatibility | Direct drop-in replacement for legacy 2N3904/BC547-based switches when bias network simplification is needed. |
Applications
| Industrial PLC Input Conditioning | Digital Logic Level Shifting |
|---|---|
Use Scenario: Converting 24 V sensor signals to 3.3 V microcontroller inputs in factory automation I/O modules. IC Role / Device Role / Timing Role: NPN digital switch with built-in biasing, acting as voltage translator and noise-filtering interface stage. Use Value: VI(off) ≤ 0.5 V rejects contact bounce and EMI; VI(on) ≥ 3 V ensures robust activation from optocoupler outputs. | Use Scenario: Interfacing 5 V legacy peripherals with 3.3 V SoC GPIOs in embedded instrumentation. IC Role / Device Role / Timing Role: Active-low level shifter using emitter-follower or common-emitter configuration. Use Value: 250 MHz fT preserves signal integrity for UART/SPI clock edges; 0.3 V VCE(sat) minimizes voltage drop in pull-down mode. |
| LED Driver for Status Indication | Relay Coil Driver in Control Panels |
Use Scenario: Driving multiplexed panel LEDs in HVAC controllers where space limits discrete resistor placement. IC Role / Device Role / Timing Role: Constant-current switch with internal base bias, replacing two-resistor + transistor subcircuit. Use Value: Integrated 4.7 kΩ resistors reduce layout complexity and eliminate solder-joint failure points in high-vibration environments. | Use Scenario: Switching 12 V/24 V relay coils in DIN-rail mounted motor starters and safety interlocks. IC Role / Device Role / Timing Role: Low-side switch with controlled turn-on/turn-off timing via resistor-defined base impedance. Use Value: 100 mA IC rating matches typical relay coil currents; 150°C TJ rating supports operation inside sealed control cabinets. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN digital transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| NSV11201T1G | Same TO-92 package; R1 = 10 kΩ, R2 = 10 kΩ; VI(on) = 3.5 V, VI(off) = 0.7 V; hFE min = 30 | Higher input thresholds suit 5 V-only systems; tighter hFE spec improves consistency in parallel-switched arrays. | Select when higher noise immunity or guaranteed gain >30 is required; verify logic-high voltage compatibility. |
| DTC114YKAT146 | SOT-23 package; R1 = 10 kΩ, R2 = 47 kΩ; VI(on) = 2.5 V, VI(off) = 0.3 V; max IC = 100 mA | Asymmetric bias enables lower VI(on); surface-mount format saves board space but requires rework capability. | Choose for compact PCBs or automated assembly; confirm VI(off) margin meets system noise floor requirements. |
Compared with NSV11201T1G and DTC114YKAT146, the FJN3301RTA offers balanced 4.7 kΩ biasing ideal for mixed 3.3 V/5 V logic domains, TO-92 through-hole reliability, and proven thermal performance in industrial ambient conditions.
Availability
FJN3301RTA is available at Aetrix Electronics and suitable for industrial PLC input conditioning, digital logic level shifting, LED status indication, and relay coil driving requiring stable component supply and long-term obsolescence management.
Supply support for FJN3301RTA 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 analog and discrete semiconductor manufacturer, acquired by ON Semiconductor in 2016; known for high-reliability power, interface, and signal-path components.
The FJN3301RTA belongs to Fairchild's digital transistor family, engineered specifically for industrial and commercial applications where simplified logic interfacing, reduced component count, and robust through-hole mounting are prioritized over ultra-miniaturization.
FAQ
What is the pin configuration of the FJN3301RTA?
The FJN3301RTA uses a standard TO-92 3L package with pin 1 = Emitter, pin 2 = Collector, pin 3 = Base. The base terminal connects internally to both bias resistors (R1 and R2), eliminating need for external base wiring in basic switching configurations. Pinout is verified per Fairchild's official datasheet Rev. 1.1 and physical dimension diagram.
Does the FJN3301RTA require external bias resistors?
No - the FJN3301RTA integrates R1 = 4.7 kΩ and R2 = 4.7 kΩ internally, forming a complete digital transistor switch. This eliminates two external resistors, reduces PCB footprint, and improves manufacturing yield. The FJN3301RTA is designed for direct connection to logic outputs without additional bias components.
What is the maximum operating temperature for the FJN3301RTA?
The FJN3301RTA has a maximum junction temperature (TJ) of 150°C and storage temperature range of –55°C to +150°C. Its thermal resistance θJA is 416°C/W on a standard FR-4 PCB, meaning it sustains full 100 mA operation at ambient temperatures up to ~85°C with adequate copper area. Derating begins above 25°C at 2.4 mW/°C.
Can the FJN3301RTA replace a standard 2N3904 transistor?
The FJN3301RTA is not a direct pin-compatible replacement for the 2N3904 because it includes internal bias resistors and uses different base connectivity. However, in digital switching applications where bias resistors are already present, the FJN3301RTA can simplify the circuit by removing those resistors - the FJN3301RTA replaces the 2N3904 plus its two base resistors as a functional unit.
What are the input voltage thresholds for turning the FJN3301RTA on and off?
The FJN3301RTA has VI(on) = 3.0 V (typical) at VCE = 0.3 V and IC = 20 mA, and VI(off) = 0.5 V (typical) at VCE = 5 V and IC = 100 μA. These thresholds provide >2.5 V hysteresis, making the FJN3301RTA robust against noise in industrial environments. Values are measured per Fairchild's datasheet test conditions and confirmed across production lots.
FJN3301RTA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Packaging:
- Bulk
- Product Status:
- Active
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 100 mA
- Voltage - Collector Emitter Breakdown (Max):
- 50 V
- Vce Saturation (Max) @ Ib, Ic:
- 300mV @ 500µA, 10mA
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 20 @ 10mA, 5V
- Power - Max:
- 300 mW
- Frequency - Transition:
- 250MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
FJN3301RTA FAQ
1.How can I place an order for FJN3301RTA through Aetrix?
Please submit a Request for Quotation (RFQ) for FJN3301RTA 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 FJN3301RTA reliable?
The price and inventory of FJN3301RTA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FJN3301RTA is usually 5 days.
3.What payment methods are accepted for FJN3301RTA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FJN3301RTA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FJN3301RTA?
FJN3301RTA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FJN3301RTA 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 FJN3301RTA?
For technical support, including FJN3301RTA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FJN3301RTA requirements.
6.How does Aetrix verify that FJN3301RTA is sourced from the original manufacturer or authorized distributors?
All FJN3301RTA 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 FJN3301RTA meets industry standards.
7.What is the process for return or replacement of FJN3301RTA?
All FJN3301RTA units undergo pre-shipment inspection (PSI). If there is an issue with FJN3301RTA, 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 FJN3301RTA part is unused and in its original packaging.
Return procedure for FJN3301RTA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
FJN3301RTA Tags
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