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

onsemi KST4403MTF

Name: KST4403MTF
Brand: onsemi
SKU: KST4403MTF
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: KST4403MTF

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: KST4403MTF.pdf

Description:: TRANS PNP 40V 0.6A SOT-23-3

Quantity:: RFQ Add To RFQ list

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Inventory:196,025

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Product details

Overview

KST4403MTF from ON Semiconductor (formerly Fairchild) is a PNP epitaxial silicon switching transistor in SOT-23 package, rated for -40 V V_CEO, -600 mA I_C, and 350 mW P_C, commonly used in low-power digital logic interface and load switching circuits.

For engineers reviewing the KST4403MTF datasheet, pinout, applications, or equivalent options, key selection criteria include verified PNP polarity, guaranteed h_FE ≥30 at I_C = -0.1 mA, V_CE(sat) ≤ -0.75 V at I_C = -500 mA, t_OFF = 255 ns, and SOT-23 footprint compatibility with standard pick-and-place equipment.

Technical Context

This device operates as a medium-speed, general-purpose PNP bipolar junction transistor optimized for saturated switching. Its design supports DC current gain (h_FE) ranging from 20 to 300 across collector currents from -0.1 mA to -500 mA, with V_BE(sat) as low as -0.75 V at I_C = -150 mA / I_B = -15 mA.

The KST4403MTF features f_T = 200 MHz at I_C = -20 mA and V_CE = -10 V, Cob = 8.5 pF at V_CB = -10 V, and fast switching performance with t_ON = 35 ns and t_OFF = 255 ns under specified test conditions.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	-40 V - Maximum allowable voltage between collector and emitter with base open; defines safe blocking capability in PNP switch configurations.
I_C	-600 mA - Continuous collector current rating; sets upper limit for load drive in saturated switching applications.
P_C	350 mW - Maximum power dissipation at T_A = 25°C; constrains thermal design in compact SOT-23 layouts.
h_FE	30–300 - DC current gain range across operating points; enables predictable base drive sizing for reliable saturation.
V_CE(sat)	-0.4 V to -0.75 V - Low saturation voltage at high current; minimizes conduction loss in active-low switch topologies.
f_T	200 MHz - Current gain bandwidth product; supports operation up to ~10–20 MHz switching frequencies with adequate gain margin.
t_OFF	255 ns - Turn-off delay under defined test conditions; determines minimum achievable switching period in pulse-width modulated loads.

Pinout & Package

SOT-23 plastic surface-mount package with gull-wing leads; 3-terminal configuration optimized for automated assembly and thermal performance in space-constrained PCBs.

Pin/Terminal	Circuit Role	Design Meaning
1	Base	Control input terminal; requires current-limited drive to achieve full saturation and avoid excessive base charge storage.
2	Emitter	Common reference node for PNP operation; connected to higher potential rail in typical high-side switch configurations.
3	Collector	Output terminal; sinks current from load to emitter when biased on; polarity must match PNP topology requirements.

Key Features

Feature	Design Value
PNP polarity with -40 V breakdown	Enables high-side switching in positive-rail systems where NPN alternatives require level-shifting circuitry.
SOT-23 footprint	Supports high-density PCB layouts and compatibility with industry-standard reflow and placement processes.
V_CE(sat) ≤ -0.75 V @ -500 mA	Reduces power loss and self-heating during sustained conduction, improving efficiency in battery-powered interfaces.
h_FE ≥ 30 @ -0.1 mA	Ensures sufficient gain for microcontroller GPIO-driven switching without external amplification stages.
f_T = 200 MHz	Provides usable gain margin for signal conditioning or RF biasing up to mid-MHz frequency ranges.

Applications

Logic-Level Interface	Low-Power Load Switch
Use Scenario: Driving TTL/CMOS-compatible inputs from microcontroller GPIO pins with limited sink capability. IC Role / Device Role: Level-shifting PNP switch that inverts and amplifies logic signals while providing current gain. Use Value: Enables direct connection of 3.3 V or 5 V MCU outputs to higher-voltage logic families without additional level translators.	Use Scenario: Controlling LED arrays, small relays, or sensor bias networks in portable instrumentation. IC Role / Device Role: Saturated PNP switch regulating current flow from supply rail to load. Use Value: Delivers -600 mA peak current with < -0.75 V saturation drop, minimizing heat generation in thermally restricted enclosures.
High-Side Power Control	Digital Signal Inversion
Use Scenario: Enabling/disabling power to subsystems such as sensors or communication modules in always-on devices. IC Role / Device Role: High-side switch placed between V_CC and load, controlled by grounded-base logic signal. Use Value: Eliminates need for high-side driver ICs or P-channel MOSFETs in cost-sensitive designs requiring simple on/off control.	Use Scenario: Generating complementary logic signals for differential receivers or clock distribution networks. IC Role / Device Role: Active inverter stage with defined propagation delay and output swing. Use Value: Provides predictable t_ON/t_OFF (35 ns / 255 ns) and rail-to-rail inversion without external pull-up resistors.

Logic-Level Interface

Low-Power Load Switch

Use Scenario: Driving TTL/CMOS-compatible inputs from microcontroller GPIO pins with limited sink capability.

IC Role / Device Role: Level-shifting PNP switch that inverts and amplifies logic signals while providing current gain.

Use Value: Enables direct connection of 3.3 V or 5 V MCU outputs to higher-voltage logic families without additional level translators.

Use Scenario: Controlling LED arrays, small relays, or sensor bias networks in portable instrumentation.

IC Role / Device Role: Saturated PNP switch regulating current flow from supply rail to load.

Use Value: Delivers -600 mA peak current with < -0.75 V saturation drop, minimizing heat generation in thermally restricted enclosures.

High-Side Power Control

Digital Signal Inversion

Use Scenario: Enabling/disabling power to subsystems such as sensors or communication modules in always-on devices.

IC Role / Device Role: High-side switch placed between V_CC and load, controlled by grounded-base logic signal.

Use Value: Eliminates need for high-side driver ICs or P-channel MOSFETs in cost-sensitive designs requiring simple on/off control.

Use Scenario: Generating complementary logic signals for differential receivers or clock distribution networks.

IC Role / Device Role: Active inverter stage with defined propagation delay and output swing.

Use Value: Provides predictable t_ON/t_OFF (35 ns / 255 ns) and rail-to-rail inversion without external pull-up resistors.

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP switching transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMBT4403	Same die, identical electrical specs; MMBT prefix denotes ON Semiconductor's standardized SOT-23 marking convention.	No functional difference; fully interchangeable in layout and schematic.	Select MMBT4403 for new designs requiring current ON Semiconductor part numbering alignment.
PN2907A	Higher V_CEO (-60 V), lower h_FE min (100), TO-92 package - larger footprint and slower t_OFF (~500 ns).	Suitable for through-hole prototyping or legacy board refreshes where SOT-23 is not available.	Choose PN2907A only when mechanical constraints permit TO-92 mounting or higher voltage margin is required.

Compared with MMBT4403, the KST4403MTF offers identical performance in SOT-23 but reflects earlier Fairchild branding; versus PN2907A, it trades voltage headroom and package size for superior switching speed and surface-mount scalability.

Availability

KST4403MTF is available at Aetrix Electronics and suitable for logic-level interface, low-power load switching, and high-side power control applications requiring stable component supply and long-term industrial availability.

Supply support for KST4403MTF 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 supplier delivering energy-efficient, high-performance silicon solutions for automotive, industrial, cloud computing, and IoT applications.

The KST4403MTF belongs to ON Semiconductor's general-purpose bipolar transistor product line, designed specifically for cost-sensitive, space-constrained digital switching applications requiring reliable PNP behavior in SOT-23 packaging.

FAQ

What is the maximum collector-emitter voltage rating for KST4403MTF?

The KST4403MTF has a maximum collector-emitter voltage (V_CEO) rating of -40 V at T_A = 25°C. This rating applies with the base open and defines the upper limit for reverse-biased voltage across the collector-emitter junction before breakdown occurs. Exceeding this value risks permanent device damage, especially under transient conditions.

Does KST4403MTF support switching at 1 MHz?

Yes, the KST4403MTF can operate reliably at 1 MHz switching frequencies. With t_ON = 35 ns and t_OFF = 255 ns, its total switching time is well below 1 µs, leaving ample dead time for control timing margins. Its f_T = 200 MHz also ensures sufficient gain at this frequency for gate drive or signal amplification tasks.

Is KST4403MTF pin-compatible with MMBT4403?

Yes, the KST4403MTF is pin-compatible with MMBT4403. Both use identical SOT-23 packages with Base-Emitter-Collector pinout (1-2-3), share identical absolute maximum ratings, and exhibit matching electrical characteristics across all published parameters including h_FE, V_CE(sat), and switching times.

What is the typical DC current gain (hFE) of KST4403MTF at 10 mA collector current?

At V_CE = -1 V and I_C = -10 mA, the KST4403MTF exhibits a typical h_FE of 100, with a guaranteed minimum of 60 per datasheet specifications. This gain level allows robust base drive design for digital switching applications while maintaining predictable saturation behavior across temperature and process variation.

Can KST4403MTF be used in linear amplifier configurations?

The KST4403MTF is characterized and optimized for switching operation, not linear amplification. While it can function in Class-A common-emitter configurations, its h_FE variation across current and temperature, lack of specified linearity parameters (e.g., distortion, noise figure), and absence of small-signal models in the datasheet make it unsuitable for precision analog gain stages.

KST4403MTF Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-236-3, SC-59, SOT-23-3

Packaging:: Bulk

Product Status:: Active

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 600 mA

Voltage - Collector Emitter Breakdown (Max):: 40 V

Vce Saturation (Max) @ Ib, Ic:: 750mV @ 50mA, 500mA

Current - Collector Cutoff (Max):: -

DC Current Gain (hFE) (Min) @ Ic, Vce:: 100 @ 150mA, 2V

Power - Max:: 350 mW

Frequency - Transition:: 200MHz

Operating Temperature:: -

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

KST4403MTF FAQ

1.How can I place an order for KST4403MTF through Aetrix?

Please submit a Request for Quotation (RFQ) for KST4403MTF 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 KST4403MTF reliable?

The price and inventory of KST4403MTF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KST4403MTF is usually 5 days.

3.What payment methods are accepted for KST4403MTF?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KST4403MTF transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for KST4403MTF?

KST4403MTF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your KST4403MTF 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 KST4403MTF?

For technical support, including KST4403MTF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KST4403MTF requirements.

6.How does Aetrix verify that KST4403MTF is sourced from the original manufacturer or authorized distributors?

All KST4403MTF 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 KST4403MTF meets industry standards.

7.What is the process for return or replacement of KST4403MTF?

All KST4403MTF units undergo pre-shipment inspection (PSI). If there is an issue with KST4403MTF, 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 KST4403MTF part is unused and in its original packaging.

Return procedure for KST4403MTF:

1.Submit a request within 90 days.

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

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