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

onsemi 2SD1825

Name: 2SD1825
Brand: onsemi
SKU: 2SD1825
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2SD1825

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-220-3 Full Pack

Datasheet:: 2SD1825.pdf

Description:: TRANS NPN DARL 60V 4A TO-220ML

Quantity:: RFQ Add To RFQ list

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Product details

Overview

2SD1825 from SANYO is an NPN epitaxial planar silicon Darlington transistor in TO-220ML package, rated for −4 A collector current, −6 V V_CEO, and 20 W collector dissipation at T_C = 25°C, designed for high-current switching in motor drivers, printer hammer drivers, and constant-voltage regulators.

For engineers reviewing the 2SD1825 datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain (h_FE ≥ 2000 at I_C = −2 A), V_CE(sat) ≤ −1.0 V at I_C/I_B = 500, switching times (t_on = 0.6 µs, t_off = 2.7 µs), and ASO curve compliance under pulsed load conditions.

Technical Context

The 2SD1825 employs a monolithic Darlington configuration with integrated base-emitter shunt resistor, enabling high DC current gain (h_FE up to 10,000) and low saturation voltage while maintaining stable operation across −40°C to +120°C ambient range. Its TO-220ML micaless package supports direct heatsink mounting without insulating washers.

Electrical behavior is characterized by V_BE(sat) ≤ −1.0 V at I_C/I_B = 500, V_CE(sat) ≤ −1.0 V under same condition, and safe operating area (SOA) validated for single-pulse durations from 1 ms to 100 ms at I_C = 4 A and V_CE ≤ 6 V - critical for inductive load switching.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−6 V: Maximum allowable collector-to-emitter voltage with base open; defines upper limit for inductive flyback clamping.
I_C (DC)	−4 A: Continuous collector current rating; determines steady-state power stage capacity in driver circuits.
P_C @ T_C=25°C	20 W: Collector power dissipation at case temperature 25°C; sets thermal design baseline for heatsink sizing.
h_FE @ I_C=−2 A	2000–5000: DC current gain at specified operating point; enables low-base-drive-current control of high-load currents.
t_on/t_off	0.6 µs / 2.7 µs: Turn-on/turn-off times at I_C = −2 A, V_CC = 20 V, R_L = 10 Ω; constrains maximum PWM frequency in switching applications.
V_CE(sat)	≤ −1.0 V @ I_C/I_B = 500: Saturation voltage defining conduction loss and junction temperature rise under full load.
ASO Boundary	Validated for 1–100 ms pulses up to I_C = 4 A and V_CE = 6 V: Confirms ruggedness against transient overloads in motor commutation.

Pinout & Package

SANYO TO-220ML micaless package: metal tab is collector (pin 2), enabling direct thermal coupling to heatsink without electrical isolation; compact footprint (10.0 × 15.5 mm) with 2.54 mm lead pitch.

Pin/Terminal	Circuit Role	Design Meaning
1	Base	Control input node; requires current-limited drive (I_B ≈ I_C/500) to achieve specified saturation performance.
2	Collector	High-current output terminal and electrically connected metal tab; must be thermally anchored but electrically isolated if system ground reference differs.
3	Emitter	Power return path; connects to load ground or negative rail; carries full load current and contributes to V_BE bias stability.

Key Features

Feature	Design Value
High DC current gain	h_FE ≥ 2000 at I_C = −2 A reduces required base drive current and simplifies gate-driver interface design.
Large current capacity	−4 A continuous / −6 A pulsed rating supports direct driving of solenoids, relays, and small DC motors without external current boosting.
Wide ASO	SOA validated for 1–100 ms pulses up to 4 A and 6 V ensures reliable operation during motor startup surges and printer impact transients.
Micaless TO-220ML	Direct-metal-tab mounting eliminates insulator thermal resistance, improving thermal impedance by ~2.5°C/W versus insulated packages.

Applications

Motor Driver Control	Printer Hammer Driver
Use Scenario: Driving 24 V DC brushed motors in industrial automation systems requiring bidirectional control via H-bridge topology. IC Role / Device Role / Timing Role: High-side or low-side switching element delivering up to 4 A peak current per half-bridge leg with <2.7 µs turn-off to minimize shoot-through risk. Use Value: Low V_CE(sat) (≤−1.0 V) reduces conduction loss to <4 W at 4 A, limiting junction temperature rise and enabling compact heatsink design.	Use Scenario: Actuating solenoid-based print hammers in dot-matrix printers where rapid on/off cycling demands robust pulse handling. IC Role / Device Role / Timing Role: Single-ended switch controlling hammer coil current with precise timing governed by t_on/t_off specs (0.6 µs / 2.7 µs). Use Value: Validated 100 ms single-pulse ASO allows full-force hammer strikes without secondary breakdown, even at elevated ambient temperatures.
Constant-Voltage Regulator	Industrial Relay Driver
Use Scenario: Series pass element in linear voltage regulators supplying stable 5 V/3 A to microcontroller subsystems in factory equipment. IC Role / Device Role / Timing Role: Linear-mode current amplifier adjusting emitter output to maintain regulated output despite input ripple and load variation. Use Value: High h_FE (≥2000) minimizes base current demand on error amplifier, preserving loop stability and reducing quiescent power draw.	Use Scenario: Driving 12 V/2 A electromagnetic relays in PLC I/O modules where contact chatter must be suppressed via clean switching edges. IC Role / Device Role / Timing Role: Final-stage switch interfacing microcontroller GPIO to relay coil, requiring fast edge rates and low saturation voltage. Use Value: V_BE(sat) ≤ −1.0 V ensures sufficient base-emitter forward bias margin across temperature, guaranteeing reliable relay pull-in down to −40°C.

Motor Driver Control

Printer Hammer Driver

Use Scenario: Driving 24 V DC brushed motors in industrial automation systems requiring bidirectional control via H-bridge topology.

IC Role / Device Role / Timing Role: High-side or low-side switching element delivering up to 4 A peak current per half-bridge leg with <2.7 µs turn-off to minimize shoot-through risk.

Use Value: Low V_CE(sat) (≤−1.0 V) reduces conduction loss to <4 W at 4 A, limiting junction temperature rise and enabling compact heatsink design.

Use Scenario: Actuating solenoid-based print hammers in dot-matrix printers where rapid on/off cycling demands robust pulse handling.

IC Role / Device Role / Timing Role: Single-ended switch controlling hammer coil current with precise timing governed by t_on/t_off specs (0.6 µs / 2.7 µs).

Use Value: Validated 100 ms single-pulse ASO allows full-force hammer strikes without secondary breakdown, even at elevated ambient temperatures.

Constant-Voltage Regulator

Industrial Relay Driver

Use Scenario: Series pass element in linear voltage regulators supplying stable 5 V/3 A to microcontroller subsystems in factory equipment.

IC Role / Device Role / Timing Role: Linear-mode current amplifier adjusting emitter output to maintain regulated output despite input ripple and load variation.

Use Value: High h_FE (≥2000) minimizes base current demand on error amplifier, preserving loop stability and reducing quiescent power draw.

Use Scenario: Driving 12 V/2 A electromagnetic relays in PLC I/O modules where contact chatter must be suppressed via clean switching edges.

IC Role / Device Role / Timing Role: Final-stage switch interfacing microcontroller GPIO to relay coil, requiring fast edge rates and low saturation voltage.

Use Value: V_BE(sat) ≤ −1.0 V ensures sufficient base-emitter forward bias margin across temperature, guaranteeing reliable relay pull-in down to −40°C.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
2SD1761	Lower I_C rating (−3 A), higher V_CEO (−8 V), same TO-220ML package and h_FE range.	Preferred for higher-voltage flyback protection where 6 V margin is insufficient, but unsuitable for >3 A continuous loads.	Select 2SD1761 when V_CE transients exceed −6 V; verify SOA curves match pulse duration and amplitude requirements.
BD679	TO-126 package (smaller footprint), lower P_C (15 W), h_FE min 750 at I_C = −2 A.	Used in space-constrained consumer electronics; lacks 2SD1825's ASO validation for >10 ms pulses.	Choose BD679 only for low-duty-cycle, low-thermal-demand applications; avoid in motor or solenoid drivers requiring sustained current.

Compared with 2SD1825, 2SD1761 trades current capacity for higher voltage tolerance, while BD679 sacrifices thermal capability and SOA robustness for board-space savings - neither offers drop-in replacement due to differing current, thermal, and pulse-handling specifications.

Availability

2SD1825 is available at Aetrix Electronics and suitable for motor driver control, printer hammer actuation, and constant-voltage regulator designs requiring stable component supply and long-term industrial availability.

Supply support for 2SD1825 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

SANYO Electric Co., Ltd. was a Japanese semiconductor manufacturer specializing in power discrete devices, analog ICs, and optoelectronics before its acquisition by Panasonic in 2011.

The 2SD1825 belongs to SANYO's high-power Darlington transistor family engineered for industrial switching applications demanding high current gain, rugged SOA, and direct-mount thermal performance.

FAQ

What is the maximum continuous collector current rating for the 2SD1825?

The 2SD1825 has a maximum continuous collector current (I_C) rating of −4 A at case temperature T_C = 25°C. This rating assumes proper heatsinking and derates linearly above 25°C per the PC–T_C curve in the datasheet. Operation beyond this limit risks secondary breakdown, especially under inductive loads.

Does the 2SD1825 require a mica insulator when mounted to a heatsink?

No, the 2SD1825 uses a micaless TO-220ML package where the metal tab is electrically connected to the collector (pin 2). It can be mounted directly to an electrically isolated heatsink without mica or silicone pads - but electrical isolation must be maintained between heatsink and system ground if collector is not at ground potential.

What is the typical DC current gain (h_FE) of the 2SD1825 at I_C = −2 A?

The 2SD1825 exhibits h_FE between 2000 and 5000 at I_C = −2 A, V_CE = −2 V, and T_A = 25°C. This high gain enables efficient base drive with minimal current from microcontrollers or logic-level drivers, reducing overall system power consumption.

Can the 2SD1825 safely switch inductive loads like relay coils or motor windings?

Yes - the 2SD1825's Safe Operating Area (ASO) is explicitly validated for single-pulse durations from 1 ms to 100 ms at I_C = 4 A and V_CE ≤ 6 V. When used with appropriate flyback diodes and snubbers, it reliably handles inductive kickback in relay and motor driver applications.

What is the collector-to-emitter saturation voltage (V_CE(sat)) specification for the 2SD1825?

The 2SD1825 specifies V_CE(sat) ≤ −1.0 V at I_C = −2 A and I_C/I_B = 500. This low saturation voltage minimizes conduction losses - e.g., <2 W at −2 A - improving thermal efficiency and enabling higher duty-cycle operation in power-switching circuits.

2SD1825 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-220-3 Full Pack

Packaging:: Bulk

Product Status:: Active

Transistor Type:: NPN - Darlington

Current - Collector (Ic) (Max):: 4 A

Voltage - Collector Emitter Breakdown (Max):: 60 V

Vce Saturation (Max) @ Ib, Ic:: 1.5V @ 4mA, 2A

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

DC Current Gain (hFE) (Min) @ Ic, Vce:: 2000 @ 2A, 2V

Power - Max:: 2 W

Frequency - Transition:: 20MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220ML

2SD1825 FAQ

1.How can I place an order for 2SD1825 through Aetrix?

Please submit a Request for Quotation (RFQ) for 2SD1825 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 2SD1825 reliable?

The price and inventory of 2SD1825 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2SD1825 is usually 5 days.

3.What payment methods are accepted for 2SD1825?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2SD1825 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2SD1825?

2SD1825 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2SD1825 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 2SD1825?

For technical support, including 2SD1825 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2SD1825 requirements.

6.How does Aetrix verify that 2SD1825 is sourced from the original manufacturer or authorized distributors?

All 2SD1825 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 2SD1825 meets industry standards.

7.What is the process for return or replacement of 2SD1825?

All 2SD1825 units undergo pre-shipment inspection (PSI). If there is an issue with 2SD1825, 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 2SD1825 part is unused and in its original packaging.

Return procedure for 2SD1825:

1.Submit a request within 90 days.

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

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