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

onsemi 2SD1803S-H

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

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Part No.:: 2SD1803S-H

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: 2SD1803S-H.pdf

Description:: TRANS NPN 50V 5A TP

Quantity:: RFQ Add To RFQ list

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Inventory:5,638

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Product details

Overview

2SD1803S-H from onsemi is an NPN bipolar junction transistor 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-H datasheet, pinout, applications, or equivalent options, this device offers verified fast switching (t_on = 50 ns, t_f = 20 ns), high f_T up to 180 MHz, and JEDEC TO-251 (TP) packaging with Pb-free and halogen-free compliance.

Technical Context

The 2SD1803S-H operates as a general-purpose NPN power switch with complementary PNP counterpart 2SB1203S-H. Its design emphasizes low saturation voltage and high current gain linearity across I_C = 0.5 A to 4 A, supporting stable gain control in linear and switching modes.

It features a TO-251 (TP) surface-mount package with four terminals - two collectors (pins 2 and 4), one emitter (pin 3), and one base (pin 1) - enabling parallel collector routing for thermal and current-handling optimization in high-power PCB layouts.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	50 V - Maximum safe collector-emitter voltage before breakdown under open-base conditions.
I_C	5 A - Continuous collector current rating at T_a = 25°C, defining usable load drive capacity.
V_CE(sat)	220–400 mV - Confirmed low saturation voltage at I_C = 3 A / I_B = 0.15 A, minimizing conduction loss.
f_T	130–180 MHz - Gain-bandwidth product measured at V_CE = –5 V, I_C = –1 A, enabling high-speed switching.
h_FE	70–400 - DC current gain range at V_CE = –2 V, covering both low- and high-current operating points.
t_f	20 ns - Measured fall time in specified test circuit, critical for minimizing switching transition losses.
P_C	1 W - Maximum power dissipation at ambient temperature, requiring thermal management above ~1.5 A continuous.

Pinout & Package

2SD1803S-H uses the TP (TO-251) surface-mount package: 7.0 mm × 5.0 mm × 2.3 mm body, single-row 4-pin leadframe with gull-wing leads, JEITA SC-64 compliant, and rated for 150°C maximum junction temperature.

Pin/Terminal	Circuit Role	Design Meaning
1	Base	Control input terminal; requires ≥0.15 A base drive for full 3 A collector conduction.
2	Collector	Main current-carrying terminal; electrically identical to pin 4 for parallel connection.
3	Emiter	Common emitter node; referenced to ground or negative rail in NPN switch configuration.
4	Collector	Second collector terminal; enables dual-path current routing to reduce trace resistance and improve thermal distribution.

Key Features

Feature	Design Value
Low V_CE(sat)	220–400 mV at 3 A ensures <1.2 W conduction loss per device, reducing heatsink requirements in 5 A switching nodes.
High f_T	Up to 180 MHz supports clean square-wave switching at >1 MHz in resonant converters and Class D amplifiers.
Linear h_FE	Stable gain across I_C = 0.5–4 A enables predictable biasing in analog driver stages and precision current sources.
Fast switching	50 ns turn-on and 20 ns fall time minimize dead-time losses and EMI generation in high-frequency PWM circuits.
TO-251 package	Surface-mount footprint with dual collectors simplifies PCB layout for high-current paths and improves thermal transfer to copper planes.

Applications

Relay Driver Circuits	DC-DC Converter Switches
Use Scenario: Driving 12 V/24 V electromagnetic relays in industrial PLC I/O modules requiring robust 3–5 A peak coil current. IC Role / Device Role / Timing Role: NPN power switch controlling relay coil current path with fast turn-off to suppress back-EMF-induced arcing. Use Value: Low V_CE(sat) reduces coil power loss; fast t_f limits flyback voltage spike duration, easing snubber design.	Use Scenario: High-side or low-side switching element in 100 kHz–1 MHz buck or boost converters delivering up to 5 A output. IC Role / Device Role / Timing Role: Main power transistor handling pulsed collector current with minimal conduction and switching loss. Use Value: Verified 180 MHz f_T and 20 ns t_f support efficient operation at 500 kHz+ without gain roll-off or timing distortion.
Inverter Output Stages	Motor Control H-Bridges
Use Scenario: Push-pull output stage in 24 V AC inverter designs powering small fans or solenoids in HVAC actuators. IC Role / Device Role / Timing Role: Complementary NPN switch paired with 2SB1203S-H PNP in totem-pole configuration for bidirectional drive. Use Value: Matched h_FE linearity and symmetric switching speed ensure balanced rise/fall times and reduced crossover distortion.	Use Scenario: Half-bridge leg in 24 V brushed DC motor controllers for robotics or power tools requiring 3–5 A continuous stall current. IC Role / Device Role / Timing Role: Low-side switch in H-bridge topology, sinking motor current during PWM on-time. Use Value: Dual-collector pinout allows direct connection to wide copper pours, lowering thermal resistance by ~15% vs. single-collector alternatives.

Relay Driver Circuits

DC-DC Converter Switches

Use Scenario: Driving 12 V/24 V electromagnetic relays in industrial PLC I/O modules requiring robust 3–5 A peak coil current.

IC Role / Device Role / Timing Role: NPN power switch controlling relay coil current path with fast turn-off to suppress back-EMF-induced arcing.

Use Value: Low V_CE(sat) reduces coil power loss; fast t_f limits flyback voltage spike duration, easing snubber design.

Use Scenario: High-side or low-side switching element in 100 kHz–1 MHz buck or boost converters delivering up to 5 A output.

IC Role / Device Role / Timing Role: Main power transistor handling pulsed collector current with minimal conduction and switching loss.

Use Value: Verified 180 MHz f_T and 20 ns t_f support efficient operation at 500 kHz+ without gain roll-off or timing distortion.

Inverter Output Stages

Motor Control H-Bridges

Use Scenario: Push-pull output stage in 24 V AC inverter designs powering small fans or solenoids in HVAC actuators.

IC Role / Device Role / Timing Role: Complementary NPN switch paired with 2SB1203S-H PNP in totem-pole configuration for bidirectional drive.

Use Value: Matched h_FE linearity and symmetric switching speed ensure balanced rise/fall times and reduced crossover distortion.

Use Scenario: Half-bridge leg in 24 V brushed DC motor controllers for robotics or power tools requiring 3–5 A continuous stall current.

IC Role / Device Role / Timing Role: Low-side switch in H-bridge topology, sinking motor current during PWM on-time.

Use Value: Dual-collector pinout allows direct connection to wide copper pours, lowering thermal resistance by ~15% vs. single-collector alternatives.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
2SD1803T-H	Same electrical specs; differs only in tape-and-reel packaging (700 pcs./reel vs. 500 pcs./bag) and TP-FA (TO-252) footprint.	Requires PCB land pattern change from TO-251 to TO-252; better thermal performance but larger board area.	Select 2SD1803T-H for automated SMT lines needing reel feed and higher power dissipation capability.
MJD127G	Higher V_CEO (80 V), lower f_T (3 MHz), same I_C (5 A); TO-252 package; no dual-collector pinout.	Lacks fast switching capability; unsuitable for >100 kHz switching; better for linear regulation or slower relay control.	Choose MJD127G when higher breakdown voltage is required and switching frequency remains below 50 kHz.

Compared with 2SD1803T-H and MJD127G, the 2SD1803S-H delivers superior high-frequency switching performance in a compact TO-251 footprint with dual-collector routing - ideal for space-constrained, medium-frequency power stages where thermal density and layout simplicity are prioritized.

Availability

2SD1803S-H is available at Aetrix Electronics and suitable for relay drivers, DC-DC converters, and motor control H-bridges requiring stable component supply, RoHS-compliant sourcing, and halogen-free manufacturing compliance.

Supply support for 2SD1803S-H 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 specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.

The 2SD1803S-H belongs to onsemi's general-purpose bipolar transistor family designed specifically for high-current, medium-speed switching in industrial controls, power supplies, and motor interfaces.

FAQ

What is the maximum collector current rating for the 2SD1803S-H?

The 2SD1803S-H has a continuous collector current rating of 5 A at T_a = 25°C. At elevated ambient temperatures or with limited PCB copper area, derating applies - e.g., ~3.5 A at 75°C ambient. The device also supports 8 A pulsed current (I_CP) for ≤1 ms duty cycles, confirmed in the official datasheet No. 2085.

Does the 2SD1803S-H have Pb-free and halogen-free compliance?

Yes, the 2SD1803S-H is explicitly marked "Pb Free and Halogen Free" in the ordering information table of the datasheet (No. 2085). It meets JESD204B and IEC 61249-2-21 standards, with material declarations available via onsemi's product environmental compliance portal.

What is the pin configuration of the 2SD1803S-H in the TP package?

The 2SD1803S-H TP (TO-251) package has four terminals: Pin 1 = Base, Pin 2 = Collector, Pin 3 = Emitter, Pin 4 = Collector. Pins 2 and 4 are internally connected to the same collector region, allowing parallel routing to reduce trace resistance and improve thermal spreading on the PCB.

How does the 2SD1803S-H compare to the 2SB1203S-H in circuit use?

The 2SD1803S-H (NPN) and 2SB1203S-H (PNP) form a complementary pair with matched V_CEO (50 V), I_C (5 A), and switching characteristics. They are jointly specified in datasheet No. 2085 and intended for use in push-pull, totem-pole, and H-bridge configurations where symmetrical drive and gain tracking are required.

What is the typical V_CE(sat) of the 2SD1803S-H at 3 A collector current?

The 2SD1803S-H exhibits a typical V_CE(sat) of 220 mV at I_C = 3 A and I_B = 0.15 A, with a maximum of 400 mV under worst-case conditions. This value is measured per the standard test circuit in datasheet No. 2085 and directly impacts conduction loss in high-current switching applications.

2SD1803S-H 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-H FAQ

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

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

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

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

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

Note: Certain payment methods may incur a processing fee.

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

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

Once your 2SD1803S-H 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-H?

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

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

All 2SD1803S-H 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-H meets industry standards.

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

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

Return procedure for 2SD1803S-H:

1.Submit a request within 90 days.

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

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