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

onsemi 2SD1803S-E

Name: 2SD1803S-E
Brand: onsemi
SKU: 2SD1803S-E
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2SD1803S-E

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-251-3 Short Leads, IPAK, TO-251AA

Datasheet:: 2SD1803S-E.pdf

Description:: TRANS NPN 50V 5A TP

Quantity:: RFQ Add To RFQ list

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Product details

Overview

2SD1803S-E from onsemi is an NPN bipolar power transistor in TP (TO-251) package, rated for 50 V V_CEO, 5 A I_C, and low 220–400 mV V_CE(sat) at I_C = 3 A / I_B = 0.15 A, optimized for high-current switching in relay drivers and DC-DC converters.

For engineers reviewing the 2SD1803S-E datasheet, pinout, applications, or equivalent options, key selection criteria include verified V_CE(sat) performance at 3 A, f_T ≥ 130 MHz, h_FE range of 70–400 (rank-dependent), TO-251 thermal dissipation capability, and Pb-free TP packaging compliance.

Technical Context

This device operates as a single NPN switching transistor with complementary PNP counterpart 2SB1203S-E. It features a planar epitaxial structure enabling fast switching (t_on = 50 ns, t_f = 20 ns) and stable h_FE linearity across collector current - critical for precision current amplification in feedback-controlled power stages.

Designed for operation up to T_j = 150°C, it supports continuous 1 W dissipation at T_a = 25°C or 20 W at T_c = 25°C with heatsinking, and exhibits low output capacitance (C_ob = 40–60 pF at V_CB = –10 V) to minimize switching losses in high-frequency inverters.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	50 V - maximum safe collector-emitter voltage under open-base conditions; defines upper rail limit in 48 V industrial switch-mode applications.
I_C	5 A - continuous DC collector current rating; supports sustained load switching in motor drivers and solenoid controls.
V_CE(sat)	220–400 mV @ I_C=3 A/I_B=0.15 A - low saturation voltage reduces conduction loss and self-heating during active switching.
f_T	130–180 MHz - gain-bandwidth product enabling stable operation up to ~50 MHz switching frequencies with adequate gain margin.
h_FE	70–400 @ V_CE=–2 V - wide DC current gain range across rank grades (Q–T); allows precise base drive sizing per application current demand.
t_f	20 ns - fast fall time minimizes overlap loss in hard-switched topologies such as half-bridge gate drivers.
P_C (T_c=25°C)	20 W - thermal power handling with case heatsinking; enables compact board-level thermal design without forced air.

Pinout & Package

2SD1803S-E uses the TP (TO-251) surface-mount package: 3-pin, single-gull-wing leadframe, JEDEC-compliant SC-64 outline, 7.0 mm × 5.0 mm footprint, 2.3 mm height, 0.315 g mass. Designed for reflow soldering and high-power PCB mounting with exposed collector pad for thermal transfer.

Pin/Terminal	Circuit Role	Design Meaning
1	Base	Control input terminal; requires 0.15 A base drive for full 3 A saturation; low V_BE(sat) (–0.95 to –1.3 V) eases driver IC selection.
2	Collector	Main power output node; electrically connected to exposed metal tab for direct thermal path to PCB copper pour or heatsink.
3	Emitter	Power return path; tied to system ground or low-side reference; must be routed with low-inductance trace for fast switching integrity.
4	Collector	Dual-collector configuration (pins 2 & 4) increases current-handling capacity and improves thermal spreading across package body.

Key Features

Feature	Design Value
Low V_CE(sat)	220–400 mV at 3 A ensures ≤1.2 W conduction loss, reducing thermal stress in sealed enclosures.
High f_T	130–180 MHz bandwidth supports clean square-wave switching up to 20–30 MHz without gain roll-off-induced distortion.
Linear h_FE	Stable DC gain vs. I_C enables predictable base resistor calculation across 0.1–4 A operating range.
Fast switching	50 ns turn-on + 500 ns storage + 20 ns fall time enables <100 ns total switching window for high-efficiency SMPS designs.
TP (TO-251) package	Surface-mount SC-64 outline with exposed collector pad delivers 20 W thermal capability without through-hole mounting or added heatsinks.

Applications

Relay Driver Circuit	DC-DC Converter Switch
Use Scenario: Driving 24 V/2 A electromagnetic relays in PLC I/O modules where space and thermal management are constrained. IC Role / Device Role / Timing Role: NPN power switch controlling relay coil current; operates in saturated on/off mode with <100 ns transition times. Use Value: Low 220–400 mV V_CE(sat) limits relay coil voltage drop to <0.4 V, ensuring reliable pull-in at minimum supply voltage.	Use Scenario: High-side switch in non-isolated buck converter delivering 5 V/3 A from 12 V input in industrial sensor nodes. IC Role / Device Role / Timing Role: Main power switching transistor; driven by PWM controller with 500 kHz switching frequency. Use Value: 130–180 MHz f_T and 20 ns t_f maintain switching fidelity and minimize dead-time losses at 500 kHz.
Inverter Half-Bridge	Motor Control Output Stage
Use Scenario: Low-side switch in 24 V H-bridge inverter driving 150 W BLDC fan with trapezoidal commutation. IC Role / Device Role / Timing Role: Fast-switching NPN element paired with complementary 2SB1203S-E; handles 3 A peak phase current. Use Value: Dual-collector (pins 2 & 4) and 20 W T_c-rated dissipation enable 100% duty-cycle operation without thermal derating.	Use Scenario: Solenoid valve driver in automated irrigation controller requiring 5 A pulsed actuation at 10 Hz. IC Role / Device Role / Timing Role: High-current linear switch activated by microcontroller GPIO via base resistor network. Use Value: Verified h_FE ≥ 70 at 4 A ensures <70 mA base drive requirement, compatible with standard 5 V MCU outputs.

Relay Driver Circuit

DC-DC Converter Switch

Use Scenario: Driving 24 V/2 A electromagnetic relays in PLC I/O modules where space and thermal management are constrained.

IC Role / Device Role / Timing Role: NPN power switch controlling relay coil current; operates in saturated on/off mode with <100 ns transition times.

Use Value: Low 220–400 mV V_CE(sat) limits relay coil voltage drop to <0.4 V, ensuring reliable pull-in at minimum supply voltage.

Use Scenario: High-side switch in non-isolated buck converter delivering 5 V/3 A from 12 V input in industrial sensor nodes.

IC Role / Device Role / Timing Role: Main power switching transistor; driven by PWM controller with 500 kHz switching frequency.

Use Value: 130–180 MHz f_T and 20 ns t_f maintain switching fidelity and minimize dead-time losses at 500 kHz.

Inverter Half-Bridge

Motor Control Output Stage

Use Scenario: Low-side switch in 24 V H-bridge inverter driving 150 W BLDC fan with trapezoidal commutation.

IC Role / Device Role / Timing Role: Fast-switching NPN element paired with complementary 2SB1203S-E; handles 3 A peak phase current.

Use Value: Dual-collector (pins 2 & 4) and 20 W T_c-rated dissipation enable 100% duty-cycle operation without thermal derating.

Use Scenario: Solenoid valve driver in automated irrigation controller requiring 5 A pulsed actuation at 10 Hz.

IC Role / Device Role / Timing Role: High-current linear switch activated by microcontroller GPIO via base resistor network.

Use Value: Verified h_FE ≥ 70 at 4 A ensures <70 mA base drive requirement, compatible with standard 5 V MCU outputs.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJD127G	Higher V_CEO (80 V), lower f_T (3 MHz), TO-252 (DPAK) package	Better suited for 48–72 V bus systems; slower switching limits use to <100 kHz.	Select when higher breakdown voltage is required and switching speed is secondary.
2SD1762	Same V_CEO/I_C, but TO-220 package; higher R_θJA; no dual-collector pinout	Requires mechanical heatsink; less suitable for dense SMT layouts; higher thermal resistance.	Choose only if legacy TO-220 footprint compatibility is mandatory and board space permits heatsink mounting.

Compared with MJD127G and 2SD1762, the 2SD1803S-E offers superior high-frequency switching (130+ MHz f_T) and lower thermal resistance in its TP package, making it optimal for compact, high-efficiency 24–48 V power stages where layout density and dynamic performance are prioritized.

Availability

2SD1803S-E is available at Aetrix Electronics and suitable for relay drivers, DC-DC converters, and motor control circuits requiring stable component supply, RoHS-compliant packaging, and consistent parametric binning across production lots.

Supply support for 2SD1803S-E 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier focused on energy-efficient innovation for automotive, industrial, cloud, and IoT applications.

The 2SD1803S-E belongs to onsemi's general-purpose bipolar power transistor family, engineered for robust high-current switching in cost-sensitive industrial controls and power conversion systems.

FAQ

What is the maximum junction temperature specification for the 2SD1803S-E?

The 2SD1803S-E has a maximum junction temperature (T_j) rating of 150°C, validated per absolute maximum ratings in the official datasheet (No. 2085). This allows operation in harsh ambient environments up to 100°C when properly heatsinked, and defines the thermal safety limit before permanent degradation occurs. Derating curves in the datasheet confirm 20 W dissipation at T_c = 25°C.

Does the 2SD1803S-E have a Pb-free and halogen-free option?

Yes - the 2SD1803S-E is explicitly marked as Pb-free in the ordering information table (No. 2085-3/10). For halogen-free compliance, the variant 2SD1803S-H is specified; the 2SD1803S-E meets RoHS but does not carry the "Halogen Free" designation. Both variants use the same TP (TO-251) package and electrical specifications.

How is the dual-collector configuration (pins 2 and 4) implemented in the 2SD1803S-E TP package?

The 2SD1803S-E TP package integrates two electrically parallel collector terminals (pins 2 and 4) bonded to the same internal die collector region. This design lowers effective bondwire inductance and spreads thermal load across two leads, improving current sharing and thermal reliability under 3–5 A pulsed loads. Pinout diagrams (No. 2085-2/10) confirm identical collector functionality for both pins.

What h_FE rank does the 'S' suffix indicate in 2SD1803S-E?

The 'S' suffix in 2SD1803S-E denotes h_FE rank S, corresponding to a DC current gain range of 140–280 at V_CE = –2 V and I_C = –0.5 A (per No. 2085-3/10). This mid-to-high gain bin enables precise base drive design for medium-current applications while maintaining consistency across production lots.

Can the 2SD1803S-E be used as a direct replacement for the 2SD1803T-E?

No - the 2SD1803S-E (TP/TO-251) and 2SD1803T-E (also TP/TO-251) share identical package and pinout but differ in h_FE rank: 'S' = 140–280, 'T' = 200–400. While electrically interchangeable in many circuits, the higher-gain 'T' variant may overdrive base networks designed for 'S', potentially causing excessive base current or instability in linear applications.

2SD1803S-E Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-251-3 Short Leads, IPAK, TO-251AA

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 5 A

Voltage - Collector Emitter Breakdown (Max):: 50 V

Vce Saturation (Max) @ Ib, Ic:: 400mV @ 150mA, 3A

Current - Collector Cutoff (Max):: 1µA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 140 @ 500mA, 2V

Power - Max:: 1 W

Frequency - Transition:: 180MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TP

2SD1803S-E FAQ

1.How can I place an order for 2SD1803S-E through Aetrix?

Please submit a Request for Quotation (RFQ) for 2SD1803S-E 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 2SD1803S-E reliable?

The price and inventory of 2SD1803S-E are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2SD1803S-E is usually 5 days.

3.What payment methods are accepted for 2SD1803S-E?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2SD1803S-E transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2SD1803S-E?

2SD1803S-E orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2SD1803S-E 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 2SD1803S-E?

For technical support, including 2SD1803S-E datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2SD1803S-E requirements.

6.How does Aetrix verify that 2SD1803S-E is sourced from the original manufacturer or authorized distributors?

All 2SD1803S-E 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 2SD1803S-E meets industry standards.

7.What is the process for return or replacement of 2SD1803S-E?

All 2SD1803S-E units undergo pre-shipment inspection (PSI). If there is an issue with 2SD1803S-E, 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 2SD1803S-E part is unused and in its original packaging.

Return procedure for 2SD1803S-E:

1.Submit a request within 90 days.

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

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