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onsemi BC817-25LT3
- Part No.:
- BC817-25LT3
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- -
- Datasheet:
-
BC817-25LT3.pdf
- Description:
- TRANSISTOR NPN 45V 500MA SOT-23
- Quantity:
- Payment:
- Shipping:
Inventory:110,000
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Product details
Overview
BC817-25LT3 from onsemi is an NPN silicon general-purpose transistor in SOT-23 package, rated for 45 V VCEO, 500 mA IC, and DC current gain (hFE) of 160–400 at IC = 100 mA. It delivers 0.7 V VCE(sat) at IC/IB = 10 and supports switching applications up to 100 MHz fT. Used in low-voltage power management and signal amplification circuits in industrial control modules.
For engineers reviewing the BC817-25LT3 datasheet, pinout, applications, or equivalent options, this page provides verified electrical parameters, thermal derating data, SOT-23 terminal mapping, AEC-Q101 qualification status, and validated alternative transistors for design-in and BOM optimization.
Technical Context
This NPN bipolar junction transistor operates in linear amplification and saturated switching modes. Its hFE range (160–400) enables stable biasing across temperature (−65°C to +150°C), while 100 MHz fT supports medium-speed digital interface buffering. The device uses epitaxial base construction for consistent gain and low leakage.
Thermal performance is defined for two board conditions: FR-5 (225 mW @ 25°C, 1.8 mW/°C derating) and alumina substrate (300 mW @ 25°C, 2.4 mW/°C derating). Junction-to-ambient RJA is 556°C/W on FR-5 and 417°C/W on alumina - critical for PCB layout decisions in thermally constrained designs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 45 V - Maximum collector-emitter voltage before breakdown; defines safe operating voltage headroom in 24 V and 36 V systems. |
| IC (continuous) | 500 mA - Continuous collector current rating; supports load switching up to ~200 mA with 2.5× safety margin. |
| hFE @ 100 mA | 160–400 - DC current gain range at IC = 100 mA, VCE = 1 V; ensures reliable base drive sizing for saturation in logic-level interfaces. |
| VCE(sat) | ≤0.7 V @ IC/IB = 10 - Low saturation voltage minimizes conduction loss in high-duty-cycle switching applications. |
| fT | 100 MHz - Current-gain bandwidth product at IC = 10 mA, VCE = 5 V; suitable for pulse shaping and low-jitter clock buffering. |
| RJA (FR-5) | 556°C/W - Thermal resistance on standard FR-5 board; requires ≥15 mm² copper pour for sustained 300 mW dissipation at TA = 70°C. |
| AEC-Q101 | Qualified - Meets automotive-grade reliability requirements for temperature cycling, HTRB, and ESD; approved for under-hood and body-control use. |
Pinout & Package
SOT-23 (Case 318, Style 6) surface-mount package with 3-pin configuration: Collector (Pin 1), Base (Pin 2), Emitter (Pin 3). Marking "6B" identifies BC817-25L variant per onsemi ordering information.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Collector | Main current output node; connects to load or pull-up; must be routed with adequate trace width for 500 mA continuous current. |
| 2 | Base | Control input; requires series resistor to limit IB and ensure saturation (e.g., 1 kΩ for 5 V TTL drive). |
| 3 | Emitter | Current return path; typically grounded in common-emitter configuration; serves as reference for VBE biasing. |
Key Features
| Feature | Design Value |
|---|---|
| Pb-free, RoHS-compliant | Meets EU Directive 2011/65/EU and halogen-free/BFR-free requirements for environmentally regulated end equipment. |
| AEC-Q101 qualified | Validated for automotive applications including engine control units and lighting drivers requiring extended temperature and lifetime reliability. |
| Low VCE(sat) | 0.7 V max at IC = 500 mA ensures <100 mW conduction loss per transistor - critical for thermally dense PCBs. |
| High hFE consistency | 160–400 range at 100 mA enables single-resistor bias networks without trimming in production assemblies. |
| 100 MHz fT | Supports clean edge transitions in 1–10 MHz digital signal routing, reducing need for external gate drivers in microcontroller I/O expansion. |
Applications
| Industrial Sensor Interface | Automotive LED Driver |
|---|---|
Use Scenario: Amplifying low-level analog signals from RTD or thermistor bridges in PLC analog input modules. IC Role / Device Role / Timing Role: NPN amplifier in common-emitter configuration with emitter degeneration for stable DC gain. Use Value: High hFE (160–400) reduces base current loading on precision op-amp buffers, preserving measurement accuracy. |
Use Scenario: Switching 350 mA LED strings in vehicle interior lighting with PWM dimming at 1 kHz. IC Role / Device Role / Timing Role: Saturated switch controlling cathode-side current path with microcontroller GPIO. Use Value: 0.7 V VCE(sat) limits power loss to ≤245 mW at full current, enabling operation without heatsink on 2-layer boards. |
| Consumer Power Supply Feedback | IoT Device Load Control |
Use Scenario: Optocoupler-driven feedback loop in 12 V offline AC/DC adapters for USB-C PD accessories. IC Role / Device Role / Timing Role: Transistor in phototransistor amplifier stage to translate isolated error signal to PWM controller. Use Value: 100 MHz fT ensures faithful reproduction of fast transient error pulses, improving dynamic regulation response. |
Use Scenario: Controlling solenoid valves and relays in smart home hubs using 3.3 V MCU outputs. IC Role / Device Role / Timing Role: Level-shifting and current-boosting interface between low-power MCU pins and inductive loads. Use Value: AEC-Q101 qualification guarantees long-term reliability in unattended deployments where field failure is unacceptable. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN general-purpose transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC817-25LT1G | Same die, SOT-23 package, but supplied in 3,000-unit tape-and-reel vs. 10,000-unit reel for BC817-25LT3G. | Identical electrical specs and thermal behavior; differs only in packaging quantity and reel orientation. | Select BC817-25LT1G for prototyping or low-volume production; BC817-25LT3G preferred for automated SMT line efficiency. |
| MMBT2222ALT1G | Higher VCEO (40 V → 60 V), lower hFE (100–300), same SOT-23 footprint and pinout. | Less gain margin at high IC; better suited for higher-voltage switching where VCEO headroom is critical. | Choose MMBT2222ALT1G when system rail exceeds 40 V or when tighter hFE tolerance is required for predictable base drive. |
Compared with BC817-25LT3, BC817-25LT1G offers identical performance in smaller reels for flexibility, while MMBT2222ALT1G trades gain for higher voltage rating - making it suitable for 48 V industrial buses where BC817-25LT3's 45 V ceiling may be marginal.
Availability
BC817-25LT3 is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive LED drivers, and IoT load control applications requiring stable component supply, AEC-Q101 compliance, and SOT-23 footprint compatibility.
Supply support for BC817-25LT3 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, sensing, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The BC817 series belongs to onsemi's general-purpose bipolar transistor product line, engineered for cost-sensitive, high-reliability applications demanding consistent gain, low saturation voltage, and automotive-grade qualification.
FAQ
What is the maximum junction temperature for BC817-25LT3?
The BC817-25LT3 has a specified junction and storage temperature range of −65°C to +150°C. This allows operation in under-hood automotive environments and industrial enclosures with minimal forced cooling. Derating curves in the datasheet confirm safe operation up to 150°C ambient when mounted on alumina substrates with appropriate thermal relief.
Is BC817-25LT3 pin-compatible with BC817-16LT3 and BC817-40LT3?
Yes, BC817-25LT3 shares identical SOT-23 pinout (Collector–Base–Emitter on Pins 1–2–3) and mechanical footprint with BC817-16LT3 and BC817-40LT3. However, hFE ranges differ: 100–250 for -16, 160–400 for -25, and 250–600 for -40. Substitution requires verification of gain-dependent circuit stability.
Does BC817-25LT3 require a base resistor in switching applications?
Yes, BC817-25LT3 requires an external base resistor to limit IB and ensure saturation. For 5 V TTL drive switching 300 mA load, a 1.2 kΩ resistor yields IB ≈ 3.7 mA (IC/IB ≈ 81), well within the hFE range and guaranteeing VCE(sat) ≤ 0.7 V as specified in the BC817-25LT3 datasheet.
What is the typical output capacitance (Cobo) of BC817-25LT3?
The BC817-25LT3 has a typical output capacitance Cobo of 10 pF measured at VCB = 10 V and f = 1.0 MHz. This value impacts high-frequency switching losses and noise coupling in RF-adjacent circuits; designers should include it in snubber network calculations for >1 MHz PWM applications.
Can BC817-25LT3 be used in linear amplifier configurations?
Yes, BC817-25LT3 supports linear operation with verified hFE vs. IC curves across −55°C to +150°C. Its 160–400 DC current gain at 100 mA and low VCE(sat) enable Class-A preamplifier stages in sensor signal chains, provided thermal design accommodates power dissipation at target Q-point.
BC817-25LT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- -
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Transistor Type:
- -
- Current - Collector (Ic) (Max):
- -
- Voltage - Collector Emitter Breakdown (Max):
- -
- Vce Saturation (Max) @ Ib, Ic:
- -
- Current - Collector Cutoff (Max):
- -
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- -
- Power - Max:
- -
- Frequency - Transition:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
BC817-25LT3 FAQ
1.How can I place an order for BC817-25LT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for BC817-25LT3 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 BC817-25LT3 reliable?
The price and inventory of BC817-25LT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC817-25LT3 is usually 5 days.
3.What payment methods are accepted for BC817-25LT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC817-25LT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC817-25LT3?
BC817-25LT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC817-25LT3 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 BC817-25LT3?
For technical support, including BC817-25LT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC817-25LT3 requirements.
6.How does Aetrix verify that BC817-25LT3 is sourced from the original manufacturer or authorized distributors?
All BC817-25LT3 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 BC817-25LT3 meets industry standards.
7.What is the process for return or replacement of BC817-25LT3?
All BC817-25LT3 units undergo pre-shipment inspection (PSI). If there is an issue with BC817-25LT3, 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 BC817-25LT3 part is unused and in its original packaging.
Return procedure for BC817-25LT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC817-25LT3 Tags
-
MMBT3906LT1G
onsemi
-
MMBT3904-7-F
Diodes Incorporated
-
MMBT3904LT1G
onsemi
-
MMBT3906-7-F
Diodes Incorporated
-
MMBT3904-TP
Micro Commercial Co
-
MMBT2222A-7-F
Diodes Incorporated
-
BC846BLT1G
onsemi
-
BC847B,215
Nexperia USA Inc.
-
SMMBT3904LT1G
onsemi
-
MMBT2222A-TP
Micro Commercial Co
-
MMBTA06LT1G
onsemi
-
MMBT2222ALT1G
onsemi
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