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onsemi BD675AG
.JPG)
- Part No.:
- BD675AG
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-225AA, TO-126-3
- Datasheet:
-
BD675AG.pdf
- Description:
- TRANS NPN DARL 45V 4A TO-126
- Quantity:
- Payment:
- Shipping:
Inventory:4,255
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Product details
Overview
BD675AG from onsemi is a plastic medium-power silicon NPN Darlington transistor designed for general-purpose amplifier output stages and switching applications requiring high DC current gain and 4.0 A continuous collector current. It features a 45 V collector-emitter breakdown voltage (VCEO), 40 W total device dissipation at TC = 25°C, and operates across –55°C to +150°C junction temperature range. It is commonly used in relay drivers, power supplies, and motor control circuits.
For engineers reviewing the BD675AG datasheet, pinout, applications, or equivalent options, key selection considerations include its TO-225 package thermal resistance (RJC = 3.13°C/W), VCE(sat) ≤ 2.8 V at IC = 2.0 A / IB = 40 mA, hFE ≥ 750 at IC = 2.0 A, and Pb-free RoHS-compliant construction.
Technical Context
The BD675AG implements a monolithic NPN Darlington pair with integrated base-emitter shunt resistor network optimized for high-current linear and switching operation. Its design supports complementary use with PNP counterparts like BD676 and BD676A in push-pull amplifier outputs.
It delivers high DC current gain (hFE ≥ 750) at 2.0 A collector current and 3.0 V VCE, with VBE(on) = 2.5 V and VCE(sat) ≤ 2.8 V under specified drive conditions - enabling efficient low-saturation switching in industrial control loads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 45 V - Maximum safe collector-emitter voltage before breakdown; defines upper rail limit in linear amplifiers or switching topologies. |
| IC | 4.0 A - Continuous collector current rating; supports driving relays, solenoids, or small motors without external heat sinking at moderate duty cycles. |
| PD @ TC = 25°C | 40 W - Total power dissipation capability at case temperature 25°C; derates linearly at 0.32 W/°C above that point. |
| hFE | ≥ 750 - Minimum DC current gain at IC = 2.0 A, VCE = 3.0 V; enables low-base-drive designs for high-current switching. |
| VCE(sat) | ≤ 2.8 V - Collector-emitter saturation voltage at IC = 2.0 A, IB = 40 mA; determines conduction loss and thermal load in saturated switch mode. |
| RJC | 3.13 °C/W - Junction-to-case thermal resistance; critical for heatsink sizing when operating near maximum power dissipation. |
Pinout & Package
BD675AG is housed in a TO-225 package (Case 77-09, Style 1), featuring three active terminals and a metal tab connected to the collector. The package provides mechanical robustness and thermal path integrity for medium-power discrete applications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Emitter | Main emitter terminal of the Darlington pair; referenced to ground or low-side return path in common-emitter configurations. |
| Pins 2 & 4 | Collector | Internally tied collector terminals; connected to heatsink via metal tab - must be electrically isolated unless intended as common collector node. |
| Pin 3 | Base | Control input for Darlington pair; requires current-limited drive due to high hFE and internal base-emitter resistors. |
Key Features
| Feature | Design Value |
|---|---|
| High DC current gain | hFE ≥ 750 at IC = 2.0 A - reduces required base drive current and simplifies driver stage design. |
| Monolithic Darlington construction | Single-die integration of driver and output transistors - improves matching, reduces parasitic inductance, and enhances reliability vs. discrete pairs. |
| Pb-free and RoHS-compliant | Meets EU Directive 2011/65/EU - eliminates lead in soldering and packaging materials for environmentally compliant manufacturing. |
| Complementary PNP pairing | Designed for direct use with BD676/BD676A in push-pull output stages - ensures matched thermal and gain characteristics in Class AB amplifiers. |
Applications
| Relay Driver Circuits | DC Motor Control (Small Brushed) |
|---|---|
|
Use Scenario: Driving 12 V/24 V electromagnetic relays with coil currents up to 3.5 A in industrial PLC I/O modules. IC Role / Device Role / Timing Role: High-gain NPN Darlington switch providing low-saturation conduction and fast turn-off with base resistor network. Use Value: Enables direct microcontroller GPIO drive without additional buffer stages, reducing BOM count and board space. |
Use Scenario: Controlling bidirectional rotation and speed of 24 V brushed DC motors in HVAC actuators and valve positioners. IC Role / Device Role / Timing Role: Low-side switching element in H-bridge half-bridge configuration, handling peak currents up to 4 A. Use Value: Delivers stable VCE(sat) ≤ 2.8 V at full load, minimizing conduction losses and thermal stress during continuous PWM operation. |
| Linear Power Supply Pass Element | Power Amplifier Output Stage |
|
Use Scenario: Series pass transistor in adjustable 0–30 V, 3 A bench power supply with foldback current limiting. IC Role / Device Role / Timing Role: Voltage-controlled current source regulating output voltage under varying load conditions. Use Value: Supports 40 W dissipation at TC = 25°C with RJC = 3.13°C/W - allows compact heatsink design while maintaining safe junction temperature. |
Use Scenario: Complementary output pair in Class AB audio amplifier delivering 10–20 W into 4 Ω or 8 Ω loads. IC Role / Device Role / Timing Role: NPN Darlington output device paired with BD676A PNP counterpart for symmetrical push-pull conduction. Use Value: Matches gain and thermal response with complementary devices, reducing crossover distortion and improving linearity at mid-power levels. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN Darlington transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BD675G | Same electrical specs but rated for hFE ≥ 750 at IC = 1.5 A (not 2.0 A); VCE(sat) tested at lower current (1.5 A/30 mA). | Suitable for lower-current linear amplifiers or intermittent switching where 2.0 A sustained drive is not required. | Select BD675G if base drive availability limits IB to ≤30 mA and peak IC stays below 1.5 A. |
| MJE800 | Higher VCEO = 60 V; identical TO-225 package and pinout; hFE ≥ 750 at IC = 1.5 A; VCE(sat) ≤ 2.5 V at same test condition. | Better suited for 48 V bus systems or higher-voltage relay/motor control where 45 V margin is insufficient. | Choose MJE800 when system voltage exceeds 40 V or when tighter VCE(sat) tolerance at 1.5 A is prioritized over 2.0 A capability. |
Compared with BD675G and MJE800, the BD675AG offers superior current-handling headroom (2.0 A test condition for hFE and VCE(sat)) while maintaining identical package and thermal performance - making it optimal for sustained 3–4 A switching in industrial control where drive current and saturation voltage stability are critical.
Availability
BD675AG is available at Aetrix Electronics and suitable for relay driver circuits, DC motor control (small brushed), and linear power supply pass elements requiring stable component supply and long-term industrial availability.
Supply support for BD675AG 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, cloud, and consumer markets.
The BD675AG belongs to onsemi's legacy medium-power bipolar transistor family, engineered for rugged, cost-effective switching and amplification in industrial control, power conversion, and electromechanical interface applications.
FAQ
What is the maximum continuous collector current rating for BD675AG?
The BD675AG is rated for a maximum continuous collector current (IC) of 4.0 A at case temperature TC = 25°C. This rating assumes adequate heatsinking and derates linearly by 0.32 W/°C above 25°C. At elevated case temperatures, the safe operating area shrinks due to thermal limitations - always verify junction temperature using RJC = 3.13°C/W and ambient conditions in your BD675AG application.
Is BD675AG pin-compatible with BD675G?
Yes, BD675AG shares identical TO-225 package (Case 77-09, Style 1) and pinout with BD675G: Pin 1 = Emitter, Pins 2 & 4 = Collector, Pin 3 = Base. However, BD675AG is characterized at higher test current (IC = 2.0 A) for hFE and VCE(sat), whereas BD675G uses IC = 1.5 A - making BD675AG preferable for sustained 2–4 A operation in your BD675AG design.
Does BD675AG require an external base resistor?
Yes, BD675AG does not integrate a base-emitter shunt resistor - unlike some Darlington variants (e.g., MPSA13). An external base resistor is required to limit base current and ensure reliable saturation. For IC = 2.0 A and hFE ≥ 750, typical IB ≈ 2.7 mA; select resistor value based on driver voltage and desired safety margin. Always verify base drive in your BD675AG circuit using actual VBE(on) = 2.5 V.
What is the safe operating area (SOA) limitation for BD675AG at 25°C?
At TC = 25°C, the BD675AG SOA is bounded by bonding wire current limit (4.0 A), thermal limit (40 W), and secondary breakdown. For example, at VCE = 20 V, maximum safe IC is ~1.5 A; at VCE = 5 V, it rises to ~4.0 A. Refer to Figure 2 in the BD675AG datasheet for full SOA curves - exceeding these boundaries risks immediate failure or accelerated degradation in your BD675AG implementation.
Is BD675AG suitable for PWM motor control?
Yes, BD675AG is widely used in PWM-driven small brushed DC motor control due to its low VCE(sat) ≤ 2.8 V at IC = 2.0 A and fast switching capability. However, ensure gate/base drive has sufficient slew rate and current capability (≥40 mA peak) to minimize transition time and switching losses. Thermal management remains critical - monitor case temperature in your BD675AG PWM application to avoid exceeding 150°C junction limit.
BD675AG Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-225AA, TO-126-3
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Transistor Type:
- NPN - Darlington
- Current - Collector (Ic) (Max):
- 4 A
- Voltage - Collector Emitter Breakdown (Max):
- 45 V
- Vce Saturation (Max) @ Ib, Ic:
- 2.8V @ 40mA, 2A
- Current - Collector Cutoff (Max):
- 500µA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 750 @ 2A, 3V
- Power - Max:
- 40 W
- Frequency - Transition:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-126
BD675AG FAQ
1.How can I place an order for BD675AG through Aetrix?
Please submit a Request for Quotation (RFQ) for BD675AG 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 BD675AG reliable?
The price and inventory of BD675AG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BD675AG is usually 5 days.
3.What payment methods are accepted for BD675AG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BD675AG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BD675AG?
BD675AG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BD675AG 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 BD675AG?
For technical support, including BD675AG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BD675AG requirements.
6.How does Aetrix verify that BD675AG is sourced from the original manufacturer or authorized distributors?
All BD675AG 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 BD675AG meets industry standards.
7.What is the process for return or replacement of BD675AG?
All BD675AG units undergo pre-shipment inspection (PSI). If there is an issue with BD675AG, 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 BD675AG part is unused and in its original packaging.
Return procedure for BD675AG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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