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

Diodes Incorporated DSS4240Y-7

Name: DSS4240Y-7
Brand: Diodes Incorporated
SKU: DSS4240Y-7
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: DSS4240Y-7

Manufacturer:: Diodes Incorporated

Category:: Single Bipolar Transistors

Package:: 6-TSSOP, SC-88, SOT-363

Datasheet:: DSS4240Y-7.pdf

Description:: TRANS NPN 40V 2A SOT-363

Quantity:: RFQ Add To RFQ list

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Inventory:32,183

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Product details

Overview

DSS4240Y-7 from Diodes Incorporated is a 40V, 2A low-V_CE(sat) NPN surface-mount transistor in SOT363 package, featuring 105 mΩ R_CE(sat) at I_C = 500 mA, 50 mA I_B, and 100 MHz f_T; used for low-power switching in automotive lighting control and portable power management circuits.

For engineers reviewing the DSS4240Y-7 datasheet, DSS4240Y-7 pinout, DSS4240Y-7 application, or DSS4240Y-7 equivalent, key selection criteria include V_CEO = 40 V, I_C = 2 A continuous, V_CE(sat) ≤ 105 mV at rated current, AEC-Q101 qualification, and SOT363 thermal resistance of 200 °C/W.

Technical Context

This NPN bipolar junction transistor uses epitaxial planar die construction optimized for low-saturation-voltage switching with fast turn-on (64 ns) and controlled storage time (275 ns). Its complementary PNP counterpart is DSS5240Y, enabling push-pull configurations.

Rated for operation from −55 °C to +150 °C and qualified to AEC-Q101, it supports automotive-grade reliability in thermally constrained PCB layouts. The SOT363 package enables dual-transistor integration with 0.006 g mass and UL 94V-0 flammability rating.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	40 V - Maximum safe collector-emitter voltage before breakdown under open-base conditions.
I_C (continuous)	2 A - Continuous collector current capability with derating above 25 °C ambient per Fig. 1.
V_CE(sat)	105 mV @ I_C = 500 mA, I_B = 50 mA - Enables <100 mW conduction loss in high-duty-cycle switching.
R_CE(sat)	105 mΩ - Directly determines on-state power dissipation in low-voltage load-switching applications.
f_T	100 MHz - Supports switching frequencies up to ~10 MHz with adequate gain margin in amplifier stages.
h_FE	350 @ I_C = 100 mA - Ensures robust base drive margin for saturated switching without overdesigning driver circuitry.
R_θJA	200 °C/W - Requires minimum pad layout per datasheet to sustain full 2 A current at T_A ≤ 70 °C.

Pinout & Package

Package: SOT363 - ultra-small 6-pin surface-mount package with dual NPN configuration (two independent transistors), molded green plastic housing, UL 94V-0 rated, 0.006 g weight, moisture sensitivity level 1.

Pin/Terminal	Circuit Role	Design Meaning
1 (C1)	Collector of Transistor 1	Primary current output node; connected to load return path in high-side switch configurations.
2 (E1)	Emitter of Transistor 1	Common emitter reference; tied to ground or low-side rail in standard switching topologies.
3 (B1)	Base of Transistor 1	Current-controlled input; requires series resistor to limit I_B to ≤300 mA peak per datasheet.
4 (B2)	Base of Transistor 2	Independent base terminal enabling dual-channel control without shared drive constraints.
5 (E2)	Emitter of Transistor 2	Second emitter node; allows isolated biasing or differential pair implementation.
6 (C2)	Collector of Transistor 2	Second collector output; supports redundant switching or complementary stage pairing with DSS5240Y.

Key Features

Feature	Design Value
Low V_CE(sat)	105 mV at 500 mA ensures <0.05 W conduction loss, reducing thermal stress in compact PCBs.
AEC-Q101 qualification	Validated for automotive temperature range (−55 °C to +150 °C) and mechanical shock/vibration requirements.
SOT363 dual-transistor layout	Enables space-efficient dual-switch implementation without discrete component placement overhead.
ESD robustness	8 kV HBM rating eliminates need for external ESD protection in board-level I/O interfaces.
Halogen- and antimony-free	Complies with RoHS and JEDEC J-STD-020 moisture sensitivity Level 1 for reflow compatibility.

Applications

Automotive LED Headlamp Driver

USB-C Power Path Switch

Use Scenario: Driving high-brightness LED strings in adaptive front-lighting systems with PWM dimming.

IC Role / Device Role / Timing Role: Low-loss NPN switch controlling LED cathode current path with fast turn-off (315 ns) to minimize PWM distortion.

Use Value: V_CE(sat) ≤ 105 mV reduces heat generation in sealed headlamp housings, supporting 2 A peak current without forced air cooling.

Use Scenario: Enabling/disabling V_BUS power delivery between USB-C source and sink during cable insertion/removal.

IC Role / Device Role / Timing Role: Load switch element providing controlled inrush current limiting and reverse-current blocking via emitter-follower configuration.

Use Value: Dual SOT363 structure allows independent control of upstream/downstream paths while maintaining <100 mΩ R_ON per channel.

Industrial Sensor Signal Conditioning

Portable Medical Device Power Sequencing

Use Scenario: Amplifying low-level analog signals from strain gauges and RTDs in battery-powered field instruments.

IC Role / Device Role / Timing Role: Linear-mode NPN amplifier stage with h_FE ≥ 350 at 100 mA ensuring stable DC gain across temperature.

Use Value: f_T = 100 MHz provides >10× bandwidth margin for 10 kHz sensor signal bandwidth, minimizing phase error.

Use Scenario: Controlling power-up sequence of microcontroller, display, and wireless module in handheld diagnostic tools.

IC Role / Device Role / Timing Role: Discrete timing-controlled switch enabling staggered V_DD ramp with external RC delay on base terminals.

Use Value: Matched dual transistors ensure consistent turn-on delay across channels, eliminating supply rail contention during startup.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
DMT3005LPS-7	30 V V_CEO, 5 A I_C, 17 mΩ R_DS(on) MOSFET; logic-level gate, no base current required.	Replaces BJT with MOSFET topology; eliminates base drive complexity but requires higher gate voltage margin.	Select when gate drive voltage ≥ 4.5 V is available and lower on-resistance is critical.
DSS5240Y-7	Complementary PNP device; identical SOT363 package, −40 V V_ECO, −2 A I_C, matched thermal characteristics.	Used in push-pull or H-bridge outputs where bidirectional current control is needed.	Select when designing complementary output stages or level-shifting circuits requiring matched NPN/PNP pairs.

Compared with DSS4240Y-7, DMT3005LPS-7 offers lower conduction loss but demands gate drive redesign, while DSS5240Y-7 enables true complementary operation without changing layout or thermal design.

Availability

DSS4240Y-7 is available at Aetrix Electronics and suitable for automotive lighting control, USB-C power path management, and industrial sensor interface applications requiring stable component supply and AEC-Q101 compliance.

Supply support for DSS4240Y-7 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, serving automotive, industrial, computing, and consumer markets with high-reliability components.

The DSS4240Y belongs to Diodes' AEC-Q101-qualified small-signal transistor product line, designed specifically for space-constrained, thermally demanding switching and amplification roles in automotive and portable electronics.

FAQ

What is the maximum continuous collector current for DSS4240Y-7 at 100°C ambient temperature?

At T_A = 100 °C, the maximum continuous collector current is derated to approximately 1.25 A based on the 200 °C/W R_θJA and 625 mW P_D rating. This assumes FR-4 PCB with minimum recommended pad layout per Figure 1 in DS31682 Rev. 2–2.

Can DSS4240Y-7 be used in linear amplifier mode, and what is its typical h_FE at 1 A collector current?

Yes, DSS4240Y-7 supports linear operation with h_FE = 150 typical at I_C = 1 A, V_CE = 2 V, per Table on page 3 of DS31682. Its f_T = 100 MHz and low noise characteristics make it suitable for low-to-mid frequency preamplifier stages.

Is the SOT363 package of DSS4240Y-7 compatible with standard reflow profiles for lead-free assembly?

Yes - the SOT363 package is RoHS-compliant and rated for moisture sensitivity Level 1 per J-STD-020, allowing exposure to ambient indefinitely and compatibility with standard IPC/JEDEC J-STD-020D reflow profiles without baking.

Does DSS4240Y-7 support bidirectional current flow like a MOSFET, or is it strictly unidirectional?

DSS4240Y-7 is a standard NPN bipolar transistor and conducts current only from collector to emitter when forward-biased. It does not support reverse current flow (emitter-to-collector) under normal operating conditions due to asymmetric junction design and low V_EBO = 5 V rating.

DSS4240Y-7 Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: 6-TSSOP, SC-88, SOT-363

Packaging:: Tape & Reel (TR)

Product Status:: Active

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 2 A

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

Vce Saturation (Max) @ Ib, Ic:: 320mV @ 200mA, 2A

Current - Collector Cutoff (Max):: 100nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 300 @ 1A, 2V

Power - Max:: 625 mW

Frequency - Transition:: 250MHz

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-363

DSS4240Y-7 FAQ

1.How can I place an order for DSS4240Y-7 through Aetrix?

Please submit a Request for Quotation (RFQ) for DSS4240Y-7 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 DSS4240Y-7 reliable?

The price and inventory of DSS4240Y-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DSS4240Y-7 is usually 5 days.

3.What payment methods are accepted for DSS4240Y-7?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DSS4240Y-7 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for DSS4240Y-7?

DSS4240Y-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your DSS4240Y-7 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 DSS4240Y-7?

For technical support, including DSS4240Y-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DSS4240Y-7 requirements.

6.How does Aetrix verify that DSS4240Y-7 is sourced from the original manufacturer or authorized distributors?

All DSS4240Y-7 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 DSS4240Y-7 meets industry standards.

7.What is the process for return or replacement of DSS4240Y-7?

All DSS4240Y-7 units undergo pre-shipment inspection (PSI). If there is an issue with DSS4240Y-7, 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 DSS4240Y-7 part is unused and in its original packaging.

Return procedure for DSS4240Y-7:

1.Submit a request within 90 days.

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

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