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

onsemi 2SD1805G-E

Name: 2SD1805G-E
Brand: onsemi
SKU: 2SD1805G-E
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2SD1805G-E

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: 2SD1805G-E.pdf

Description:: TRANS NPN 20V 5A TP

Quantity:: RFQ Add To RFQ list

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Product details

Overview

2SD1805G-E from onsemi is an NPN bipolar junction transistor (BJT) optimized for high-current switching in compact power interfaces, featuring V_CEO = 20 V, I_C = 5 A continuous, V_CE(sat) = 220 mV (typ.) at I_C = 3 A / I_B = 60 mA, and f_T = 120 MHz - used in lamp drivers, relay drivers, and strobe circuits where low saturation loss and fast turn-on/turn-off are critical.

For engineers reviewing the 2SD1805G-E datasheet, pinout, applications, or equivalent options, key selection criteria include verified h_FE rank G (280–560 at I_C = 500 mA), DPAK/TP-FA package thermal performance (P_C = 15 W at T_C = 25°C), switching times (t_on = 30 ns, t_stg = 300 ns), and Pb-free compliance per J-STD-609.

Technical Context

This device operates as a single NPN switch with base-controlled current amplification, designed for DC and pulsed switching up to 8 A peak (I_CP). Its low V_CE(sat) and high h_FE rank G enable efficient drive of inductive loads without external gain staging.

The DPAK/TP-FA package provides direct heatsink mounting capability and supports high-power dissipation (15 W at case temperature 25°C), while its 3-pin configuration (Emitter, Base, Collector) aligns with standard TO-252 footprint layouts for board-level thermal management.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	20 V - Maximum safe collector-emitter voltage under open-base conditions; defines upper limit for relay coil or lamp supply rail compatibility.
I_C	5 A - Continuous collector current rating; supports sustained 5 A load switching without derating at T_C ≤ 25°C.
V_CE(sat)	220 mV (typ.) at I_C = 3 A / I_B = 60 mA - Low conduction loss enables <1.5 W power dissipation in saturated switching mode.
f_T	120 MHz - Gain-bandwidth product confirms suitability for high-speed digital switching (e.g., strobe flash control) up to ~10–20 MHz effective edge rates.
h_FE Rank	G (280–560 at V_CE = 2 V, I_C = 500 mA) - Tight DC gain bin ensures predictable base drive requirements across production lots.
t_on/t_f	30 ns / 40 ns - Fast switching transitions minimize overlap loss in PWM-driven loads such as LED arrays or solenoid actuators.

Pinout & Package

DPAK / TP-FA package (Case 369AH), surface-mount, 3-terminal configuration with exposed drain pad (Collector) for thermal conduction to PCB copper or heatsink.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal	Connected to ground or low-side return path; carries full load current and must be routed with low-inductance, wide copper pour.
2 (Base)	Control input	Receives current-limited drive signal (I_B = 60 mA typical for 3 A I_C); requires series resistor to prevent overdrive and ensure stable h_FE-based gain.
3 (Collector)	High-side load connection	Connected to positive supply rail or inductive load; electrically and thermally tied to exposed metal tab for enhanced heat transfer.

Key Features

Feature	Design Value
Low V_CE(sat)	220 mV typ. at 3 A - Reduces conduction loss by >40% vs. standard general-purpose BJTs, lowering thermal stress in 5 A lamp driver stages.
Large I_C capacity	5 A continuous / 8 A pulse - Enables single-transistor replacement of paralleled devices in relay driver modules, simplifying layout and BOM.
Fast switching	t_on = 30 ns, t_f = 40 ns - Supports clean 10–20 MHz digital switching edges, minimizing shoot-through risk in half-bridge auxiliary controls.
Small DPAK footprint	TP-FA outline (Case 369AH) - Delivers 15 W thermal capability in 6.7 × 6.2 mm area, enabling high-density placement in space-constrained strobe PCBs.

Applications

Lamp Drivers	Relay Drivers
Use Scenario: Driving incandescent or halogen lamps in automotive interior lighting or industrial panel indicators with PWM dimming. IC Role / Device Role / Timing Role: NPN switch controlling lamp current path between supply rail and ground; operated in saturation for minimal power loss. Use Value: V_CE(sat) ≤ 500 mV ensures <2.5 W dissipation at 5 A, eliminating need for auxiliary heatsinks in ambient-temperature enclosures.	Use Scenario: Energizing 12 V or 24 V electromagnetic relays in PLC output modules and HVAC control panels. IC Role / Device Role / Timing Role: High-current interface between microcontroller GPIO and relay coil; handles inductive kickback via external flyback diode. Use Value: 5 A I_C rating supports coils drawing up to 4.5 A, covering >95% of industrial signal relays without derating.
Strobe Circuits	Voltage Regulators
Use Scenario: Triggering xenon flash tubes or high-intensity LED strobes in machine vision systems and emergency signaling equipment. IC Role / Device Role / Timing Role: Fast-switching NPN switch discharging storage capacitor into flash load; operates in pulse mode with I_CP = 8 A capability. Use Value: 30 ns t_on and 40 ns t_f enable precise sub-microsecond flash timing control, critical for synchronization with camera exposure windows.	Use Scenario: Pass transistor in linear voltage regulators delivering up to 5 A output current for FPGA core rails or analog subsystems. IC Role / Device Role / Timing Role: Series pass element controlled by error amplifier feedback loop; biased in active region for regulation. Use Value: h_FE rank G (280–560) ensures stable base current demand across temperature, reducing regulator loop compensation complexity.

Lamp Drivers

Relay Drivers

Use Scenario: Driving incandescent or halogen lamps in automotive interior lighting or industrial panel indicators with PWM dimming.

IC Role / Device Role / Timing Role: NPN switch controlling lamp current path between supply rail and ground; operated in saturation for minimal power loss.

Use Value: V_CE(sat) ≤ 500 mV ensures <2.5 W dissipation at 5 A, eliminating need for auxiliary heatsinks in ambient-temperature enclosures.

Use Scenario: Energizing 12 V or 24 V electromagnetic relays in PLC output modules and HVAC control panels.

IC Role / Device Role / Timing Role: High-current interface between microcontroller GPIO and relay coil; handles inductive kickback via external flyback diode.

Use Value: 5 A I_C rating supports coils drawing up to 4.5 A, covering >95% of industrial signal relays without derating.

Strobe Circuits

Voltage Regulators

Use Scenario: Triggering xenon flash tubes or high-intensity LED strobes in machine vision systems and emergency signaling equipment.

IC Role / Device Role / Timing Role: Fast-switching NPN switch discharging storage capacitor into flash load; operates in pulse mode with I_CP = 8 A capability.

Use Value: 30 ns t_on and 40 ns t_f enable precise sub-microsecond flash timing control, critical for synchronization with camera exposure windows.

Use Scenario: Pass transistor in linear voltage regulators delivering up to 5 A output current for FPGA core rails or analog subsystems.

IC Role / Device Role / Timing Role: Series pass element controlled by error amplifier feedback loop; biased in active region for regulation.

Use Value: h_FE rank G (280–560) ensures stable base current demand across temperature, reducing regulator loop compensation complexity.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJD1805GRLG	Same h_FE rank G, identical DPAK package, but rated for V_CEO = 25 V and I_C = 6 A; slightly higher V_CE(sat) (250 mV typ.)	Supports marginally higher supply rails (e.g., 24 V industrial buses); better suited for 6 A continuous loads with tighter thermal budget.	Select when V_CEO > 20 V or I_C > 5 A is required; otherwise, 2SD1805G-E offers lower saturation loss at 5 A.
2SD2142-Y	TO-252 package, V_CEO = 20 V, I_C = 5 A, but h_FE rank Y (120–240); f_T = 100 MHz; no Pb-free certification	Lower gain requires higher base drive current; slower switching limits use in high-frequency strobes; not compliant with RoHS lead-free mandates.	Consider only for legacy designs where Pb content is acceptable and gain variability is manageable via design margin.

Compared with MJD1805GRLG and 2SD2142-Y, the 2SD1805G-E delivers the lowest V_CE(sat) among 20 V/5 A DPAK NPN transistors with certified Pb-free construction, making it optimal for thermally constrained lamp and relay drivers requiring regulatory compliance and efficiency.

Availability

2SD1805G-E is available at Aetrix Electronics and suitable for lamp drivers, relay drivers, strobe circuits, and linear voltage regulators requiring stable component supply, RoHS-compliant manufacturing, and consistent h_FE binning for production scalability.

Supply support for 2SD1805G-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 2SD1805G-E belongs to onsemi's general-purpose power transistor family, engineered specifically for high-current, low-saturation switching in space- and thermally-constrained industrial control and lighting systems.

FAQ

What is the h_FE range for the 2SD1805G-E, and how is it binned?

The 2SD1805G-E is binned to h_FE Rank G, with a guaranteed DC current gain of 280 to 560 measured at V_CE = 2 V and I_C = 500 mA. This tight bin ensures predictable base drive requirements across production units, reducing design margin needed for relay or lamp driver circuits. The 2SD1805G-E datasheet explicitly defines this ranking on page 2 under "DC Current Gain".

Is the 2SD1805G-E RoHS-compliant and Pb-free?

Yes, the 2SD1805G-E is a certified Pb-free device, meeting J-STD-609 Class 3 requirements. The datasheet states "This is a Pb−Free Device" on page 1 and specifies "(Pb−Free)" in the ordering information table for the 2SD1805G-E variant. All onsemi DPAK-packaged transistors ordered with the '-E' suffix comply with RoHS Directive 2011/65/EU.

What is the maximum power dissipation of the 2SD1805G-E at 25°C case temperature?

The 2SD1805G-E has a maximum collector dissipation (P_C) of 15 W when mounted on a heatsink or PCB copper area maintaining T_C = 25°C, as specified in the Absolute Maximum Ratings table on page 1 of the datasheet. At ambient temperature (T_A = 25°C) with no heatsink, P_C drops to 1 W - confirming the necessity of thermal management for high-current operation.

Can the 2SD1805G-E replace the 2SD1805F-E in existing designs?

Yes, the 2SD1805G-E can directly replace the 2SD1805F-E in most applications because both share identical package (DPAK/TP-FA), voltage/current ratings, and thermal specifications. The only difference is h_FE binning: F rank is 160–320, while G rank is 280–560. Higher gain in the 2SD1805G-E may reduce required base drive current, improving efficiency in relay or lamp driver stages.

What are the recommended layout practices for thermal management of the 2SD1805G-E?

For optimal thermal performance, the 2SD1805G-E's exposed Collector pad (Pin 3) must be soldered to a minimum 250 mm² copper pour on the PCB, preferably with ≥4 thermal vias to inner or backside ground planes. The datasheet's Case 369AH mechanical drawing specifies the pad dimensions and solder mask opening. Avoid narrow traces on Collector or Emitter paths to prevent localized heating during 5 A operation.

2SD1805G-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):: 20 V

Vce Saturation (Max) @ Ib, Ic:: 500mV @ 60mA, 3A

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

DC Current Gain (hFE) (Min) @ Ic, Vce:: 280 @ 500mA, 2V

Power - Max:: 1 W

Frequency - Transition:: 120MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TP

2SD1805G-E FAQ

1.How can I place an order for 2SD1805G-E through Aetrix?

Please submit a Request for Quotation (RFQ) for 2SD1805G-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 2SD1805G-E reliable?

The price and inventory of 2SD1805G-E are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2SD1805G-E is usually 5 days.

3.What payment methods are accepted for 2SD1805G-E?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2SD1805G-E transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2SD1805G-E?

2SD1805G-E orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2SD1805G-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 2SD1805G-E?

For technical support, including 2SD1805G-E datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2SD1805G-E requirements.

6.How does Aetrix verify that 2SD1805G-E is sourced from the original manufacturer or authorized distributors?

All 2SD1805G-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 2SD1805G-E meets industry standards.

7.What is the process for return or replacement of 2SD1805G-E?

All 2SD1805G-E units undergo pre-shipment inspection (PSI). If there is an issue with 2SD1805G-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 2SD1805G-E part is unused and in its original packaging.

Return procedure for 2SD1805G-E:

1.Submit a request within 90 days.

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

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