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onsemi KST14MTF
- Part No.:
- KST14MTF
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
KST14MTF.pdf
- Description:
- TRANS NPN DARL 30V 0.3A SOT-23-3
- Quantity:
- Payment:
- Shipping:
Inventory:8,660
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Product details
Overview
KST14MTF from ON Semiconductor is a Darlington NPN epitaxial silicon transistor in SOT-23 package, rated for 30 V VCEO, 300 mA IC, and 350 mW PC, with hFE ≥10,000 at IC = 100 mA and VCE = 5 V, used in low-power switching and signal amplification circuits such as sensor interface stages and LED drivers.
For engineers reviewing the KST14MTF datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed high DC gain at medium collector current, low saturation voltage under defined drive conditions, SOT-23 footprint compatibility, and suitability for discrete Darlington configurations requiring minimal base drive.
Technical Context
The KST14MTF implements a monolithic Darlington pair structure with integrated emitter resistor, delivering high current gain without external bias components. It operates as a single-stage current amplifier with fixed polarity (NPN) and requires no external feedback or compensation networks.
Its electrical behavior is characterized by VCE(sat) ≤ 1.5 V at IC = 100 mA / IB = 0.1 mA and fT = 125 MHz at VCE = 5 V / IC = 10 mA - indicating usable bandwidth beyond audio frequencies while maintaining high gain stability in DC-coupled amplifiers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 30 V - supports operation in 24 V rail systems with margin against transients |
| IC | 300 mA - enables direct driving of small relays or indicator LEDs without buffer stage |
| hFE | ≥10,000 at IC = 100 mA - reduces required base drive current to ≤10 µA for full conduction |
| VCE(sat) | ≤1.5 V at IC = 100 mA / IB = 0.1 mA - limits power loss to ≤150 mW in saturated switch mode |
| fT | 125 MHz - allows stable small-signal amplification up to ~10 MHz with gain >10 |
| PD | 350 mW - defines maximum continuous dissipation in free-air SOT-23 mounting |
Pinout & Package
SOT-23 plastic surface-mount package with gull-wing leads; standardized 3-pin outline per JEDEC TO-236AB; thermal resistance RθJA ≈ 357°C/W in typical PCB layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base | Input control terminal; accepts low-current drive to enable high-gain switching |
| 2 | Emitter | Common reference node; internally connected to emitter of second transistor in Darlington pair |
| 3 | Collector | Output current path; delivers amplified load current with minimal voltage drop in saturation |
Key Features
| Feature | Design Value |
|---|---|
| Monolithic Darlington structure | Integrates two NPN transistors and emitter resistor on one die, eliminating external component count and layout sensitivity |
| Guaranteed hFE ≥10K | Ensures predictable turn-on behavior across temperature and process variation without gain binning |
| SOT-23 footprint | Enables high-density placement in space-constrained applications like portable instrumentation and wearables |
| VBE(on) = 2.0 V | Defines minimum base-emitter forward bias needed for conduction - compatible with 3.3 V and 5 V logic outputs |
Applications
| Industrial Sensor Interface | Low-Power LED Driver |
|---|---|
Use Scenario: Amplifying microamp-level output from resistive temperature detectors (RTDs) or photodiodes before ADC input. IC Role / Device Role / Timing Role: Discrete current amplifier providing gain ≥10,000 with minimal input loading. Use Value: Eliminates need for op-amp biasing network; achieves 16-bit-equivalent resolution with simple passive filtering. | Use Scenario: Driving 20–30 mA indicator LEDs from microcontroller GPIO pins with limited sink/source capability. IC Role / Device Role / Timing Role: High-gain switch enabling full LED brightness with ≤10 µA base current. Use Value: Reduces MCU I/O stress and eliminates external base resistor calculation errors. |
| Relay Coil Driver | Discrete Logic-Level Translator |
Use Scenario: Controlling 12 V/24 V electromagnetic relays in PLC I/O modules where isolation is handled separately. IC Role / Device Role / Timing Role: Saturated switch delivering 100–200 mA coil current with <1.5 V dropout. Use Value: Ensures reliable relay pull-in at low supply voltages and extends contact life via clean switching edges. | Use Scenario: Level-shifting between 1.8 V logic domains and 3.3 V peripherals in mixed-voltage embedded systems. IC Role / Device Role / Timing Role: Inverting translator with defined VBE(on) threshold and fast turn-off due to Darlington architecture. Use Value: Provides deterministic switching point without hysteresis or external bias components. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Darlington transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMDT3904-7-F | Single NPN (not Darlington); hFE = 100–300 at IC = 10 mA; VCE(sat) = 0.2 V at IC = 10 mA | Lower gain requires higher base drive; better for high-speed switching, not low-current amplification | Select when speed >100 ns switching and gain <300 is acceptable |
| NSV60601M3T5G | High-gain NPN (hFE ≥1000 at IC = 100 mA); same SOT-23 package; VCE(sat) = 0.25 V | Not a Darlington; faster response but lower gain margin; optimized for automotive load switching | Select when lower VCE(sat) and AEC-Q101 qualification are required over ultra-low base current |
Compared with MMDT3904-7-F and NSV60601M3T5G, the KST14MTF uniquely delivers ultra-high DC gain in a standard SOT-23 footprint, making it irreplaceable in applications where base drive current must be minimized below 10 µA while maintaining robust saturation performance.
Availability
KST14MTF is available at Aetrix Electronics and suitable for industrial sensor interfaces, low-power LED drivers, relay coil drivers, and discrete logic-level translators requiring stable component supply and long-term manufacturability.
Supply support for KST14MTF 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, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The KST14MTF belongs to ON Semiconductor's legacy discrete transistor portfolio inherited from Fairchild, designed specifically for cost-sensitive, high-gain, low-base-drive switching and amplification in space-constrained applications.
FAQ
What is the maximum collector current rating for the KST14MTF?
The KST14MTF has a maximum continuous collector current rating of 300 mA at TA = 25°C. Derating is required above ambient temperatures - for example, at 70°C ambient, the usable IC drops to approximately 220 mA based on its 350 mW power dissipation limit and thermal resistance. Always verify actual junction temperature in final layout using measured board thermal performance.
Does the KST14MTF require an external base resistor?
Yes, the KST14MTF requires an external base resistor to limit base current and ensure proper saturation. Although its Darlington structure provides high hFE, uncontrolled base drive can cause excessive power dissipation or thermal runaway. Typical designs use 10–100 kΩ resistors depending on source voltage and desired switching speed.
Is the KST14MTF pin-compatible with the KST13MTF?
Yes, the KST14MTF and KST13MTF share identical SOT-23 pinout (Base–Emitter–Collector on pins 1–2–3) and mechanical footprint. However, they differ electrically: KST13MTF has hFE ≥5,000 at IC = 10 mA, while KST14MTF guarantees hFE ≥10,000 at IC = 100 mA - making them functionally distinct despite physical compatibility.
What is the typical VCE(sat) of the KST14MTF under standard test conditions?
The typical VCE(sat) of the KST14MTF is 1.5 V when tested at IC = 100 mA and IB = 0.1 mA. This value reflects worst-case saturation performance under defined drive; actual measurements in circuit may range from 1.2 V to 1.5 V depending on PCB trace resistance, temperature, and device variation.
Can the KST14MTF be used in linear amplification applications?
The KST14MTF is characterized for switching and moderate-gain amplification, not precision linear operation. Its Darlington structure introduces nonlinearities and thermal drift unsuitable for high-fidelity analog amplification. For linear use, it should be restricted to Class-A biased stages with narrow output swing and verified stability - never as a general-purpose audio or instrumentation amplifier replacement.
KST14MTF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Transistor Type:
- NPN - Darlington
- Current - Collector (Ic) (Max):
- 300 mA
- Voltage - Collector Emitter Breakdown (Max):
- 30 V
- Vce Saturation (Max) @ Ib, Ic:
- 1.5V @ 100µA, 100mA
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 20000 @ 100mA, 5V
- Power - Max:
- 350 mW
- Frequency - Transition:
- 125MHz
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
KST14MTF FAQ
1.How can I place an order for KST14MTF through Aetrix?
Please submit a Request for Quotation (RFQ) for KST14MTF 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 KST14MTF reliable?
The price and inventory of KST14MTF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KST14MTF is usually 5 days.
3.What payment methods are accepted for KST14MTF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KST14MTF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for KST14MTF?
KST14MTF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your KST14MTF 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 KST14MTF?
For technical support, including KST14MTF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KST14MTF requirements.
6.How does Aetrix verify that KST14MTF is sourced from the original manufacturer or authorized distributors?
All KST14MTF 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 KST14MTF meets industry standards.
7.What is the process for return or replacement of KST14MTF?
All KST14MTF units undergo pre-shipment inspection (PSI). If there is an issue with KST14MTF, 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 KST14MTF part is unused and in its original packaging.
Return procedure for KST14MTF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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