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

onsemi BC817-25LT1

Name: BC817-25LT1
Brand: onsemi
SKU: BC817-25LT1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BC817-25LT1

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: BC817-25LT1.pdf

Description:: TRANS NPN 45V 0.5A SOT23-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BC817-25LT1 from onsemi is an NPN silicon general-purpose transistor in SOT-23 package, rated for 45 V V_CEO, 500 mA continuous collector current, and DC current gain (h_FE) of 160–400 at I_C = 100 mA / V_CE = 1.0 V. It serves as a low-voltage switching or linear amplification device in power management, signal buffering, and interface logic circuits.

For engineers reviewing the BC817-25LT1 datasheet, pinout, applications, or equivalent options, key selection criteria include its guaranteed h_FE range, low V_CE(sat) ≤ 0.7 V at I_C = 500 mA / I_B = 50 mA, thermal resistance of 556 °C/W on FR-5 board, AEC-Q101 qualification, and Pb-free RoHS-compliant SOT-23 footprint.

Technical Context

This discrete NPN transistor operates in active, saturation, and cutoff regions with verified switching performance: t_d = 85 ns, t_r = 30 ns, t_s = 1000 ns, and t_f = 300 ns under V_CC = 3.0 V, I_C = 10 mA conditions. Its f_T = 100 MHz at I_C = 10 mA / V_CE = 5.0 V supports medium-frequency amplification and digital switching up to ~10 MHz.

Thermal design is constrained by R_JA = 556 °C/W on standard FR-5 PCB (1.0 × 0.75 × 0.062 in), derating at 1.8 mW/°C above 25°C, and maximum junction temperature of +150°C. Safe operating area (SOA) data confirms single-pulse capability up to 1 A at 10 V with 10 ms pulse width.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	45 V - Maximum collector-emitter voltage before breakdown; defines safe DC bias headroom in 24 V and 36 V systems.
I_C (continuous)	500 mA - Continuous collector current rating; supports load switching up to ~200 mW dissipation at room temperature.
h_FE	160–400 - Guaranteed DC current gain range at I_C = 100 mA / V_CE = 1.0 V; enables predictable base drive sizing for saturated switching.
V_CE(sat)	≤ 0.7 V - Collector-emitter saturation voltage at I_C = 500 mA / I_B = 50 mA; limits conduction loss to < 350 mW in switch applications.
f_T	100 MHz - Current-gain bandwidth product at I_C = 10 mA / V_CE = 5.0 V; validates use in audio preamps and clock buffer stages.
R_JA	556 °C/W - Junction-to-ambient thermal resistance on FR-5 board; requires heatsinking or derating above 75°C ambient.
AEC-Q101	Qualified - Meets automotive reliability stress test requirements; suitable for under-hood and infotainment subsystems.

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 datasheet page 2.

Pin/Terminal	Circuit Role	Design Meaning
1 (Collector)	Current sink node	Connected to load return path; must withstand 45 V transient spikes and conduct up to 500 mA continuously.
2 (Base)	Control input	Receives current-limited drive (e.g., 5–50 mA); requires series resistor to ensure h_FE-based saturation across temperature.
3 (Emitter)	Reference terminal	Typically grounded or tied to common emitter node; carries full collector current and defines V_BE(on) threshold (~0.7–1.2 V).

Key Features

Feature	Design Value
AEC-Q101 qualified	Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per JESD47.
Pb-free, RoHS compliant	Meets EU Directive 2011/65/EU and halogen-free/BFR-free requirements for green manufacturing.
Guaranteed h_FE binning	160–400 range ensures consistent gain behavior across production lots-critical for analog feedback and current mirror designs.
Low V_CE(sat)	≤ 0.7 V at rated current reduces power loss and self-heating in high-duty-cycle switching applications.
High f_T	100 MHz bandwidth supports stable operation in 10–20 MHz clock distribution and RF detector front-ends.

Applications

Industrial PLC Output Stage	Automotive LED Driver
Use Scenario: Driving 24 V solenoid valves and relay coils in programmable logic controller output modules. IC Role / Device Role / Timing Role: NPN switch controlling load current via microcontroller GPIO with opto-isolated base drive. Use Value: 45 V V_CEO accommodates inductive kickback suppression; 500 mA rating covers typical 20–300 mA valve loads without external heat sinking.	Use Scenario: Constant-current dimming control for interior map lights and dashboard backlighting in passenger vehicles. IC Role / Device Role / Timing Role: Linear current regulator stage with PWM-controlled base bias to set LED brightness. Use Value: AEC-Q101 qualification ensures lifetime reliability; h_FE consistency enables accurate current scaling across temperature (-40°C to +125°C).
Consumer Appliance Motor Control	IoT Sensor Interface Buffer
Use Scenario: Low-side switching of small DC brush motors (e.g., HVAC blower, coffee grinder) in white goods. IC Role / Device Role / Timing Role: Saturated switch interfacing MCU PWM output to motor winding with flyback diode protection. Use Value: V_CE(sat) ≤ 0.7 V minimizes conduction loss at 300–400 mA loads; SOT-23 footprint enables compact dual-motor driver layouts.	Use Scenario: Level-shifting and signal conditioning between 1.8 V sensor ICs and 3.3 V microcontrollers in battery-powered edge nodes. IC Role / Device Role / Timing Role: Active pull-up/pull-down amplifier for open-drain I²C lines or analog sensor output buffering. Use Value: f_T = 100 MHz supports clean 400 kHz I²C timing; low C_obo = 10 pF prevents signal integrity degradation on high-impedance traces.

Industrial PLC Output Stage

Automotive LED Driver

Use Scenario: Driving 24 V solenoid valves and relay coils in programmable logic controller output modules.

IC Role / Device Role / Timing Role: NPN switch controlling load current via microcontroller GPIO with opto-isolated base drive.

Use Value: 45 V V_CEO accommodates inductive kickback suppression; 500 mA rating covers typical 20–300 mA valve loads without external heat sinking.

Use Scenario: Constant-current dimming control for interior map lights and dashboard backlighting in passenger vehicles.

IC Role / Device Role / Timing Role: Linear current regulator stage with PWM-controlled base bias to set LED brightness.

Use Value: AEC-Q101 qualification ensures lifetime reliability; h_FE consistency enables accurate current scaling across temperature (-40°C to +125°C).

Consumer Appliance Motor Control

IoT Sensor Interface Buffer

Use Scenario: Low-side switching of small DC brush motors (e.g., HVAC blower, coffee grinder) in white goods.

IC Role / Device Role / Timing Role: Saturated switch interfacing MCU PWM output to motor winding with flyback diode protection.

Use Value: V_CE(sat) ≤ 0.7 V minimizes conduction loss at 300–400 mA loads; SOT-23 footprint enables compact dual-motor driver layouts.

Use Scenario: Level-shifting and signal conditioning between 1.8 V sensor ICs and 3.3 V microcontrollers in battery-powered edge nodes.

IC Role / Device Role / Timing Role: Active pull-up/pull-down amplifier for open-drain I²C lines or analog sensor output buffering.

Use Value: f_T = 100 MHz supports clean 400 kHz I²C timing; low C_obo = 10 pF prevents signal integrity degradation on high-impedance traces.

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
BC817-25LT3G	Same die, 10,000-piece tape-and-reel packaging vs. 3,000-piece for BC817-25LT1G; identical electrical specs.	No functional difference; suited for high-volume automated assembly where reel size impacts feeder setup.	Select BC817-25LT3G for production runs ≥50k units to reduce changeover frequency and material handling cost.
MMBT2222ALT1G	Higher V_CEO = 40 V (vs. 45 V), lower h_FE min = 100, higher V_CE(sat) = 1.0 V at same I_C/I_B; same SOT-23 package.	Less margin for inductive transients; less efficient in high-current saturation; acceptable for 5–100 mA logic-level switching.	Choose MMBT2222ALT1G only when legacy design reuse or second-source validation mandates identical pinout with relaxed gain/voltage requirements.

Compared with BC817-25LT1, BC817-25LT3G offers identical performance in larger reels for volume efficiency, while MMBT2222ALT1G trades gain and saturation voltage for broader legacy compatibility-neither is pin-compatible without verifying layout clearance for thermal pad variants.

Availability

BC817-25LT1 is available at Aetrix Electronics and suitable for industrial PLC output stages, automotive LED drivers, and consumer appliance motor control requiring stable component supply, AEC-Q101 compliance, and SOT-23 footprint consistency.

Supply support for BC817-25LT1 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 (Nasdaq: ON) is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The BC817 series belongs to onsemi's general-purpose bipolar transistor portfolio, engineered for robustness in harsh environments and designed to replace legacy TO-92 devices with superior thermal performance and automated assembly compatibility.

FAQ

What is the maximum continuous collector current rating for BC817-25LT1?

The BC817-25LT1 has a maximum continuous collector current (I_C) rating of 500 mA at T_A = 25°C on FR-5 board. Derating applies above 25°C at 1.8 mW/°C, limiting usable current to ~350 mA at 75°C ambient. This rating assumes proper PCB copper pour and no additional heatsinking.

Does BC817-25LT1 meet automotive reliability standards?

Yes, BC817-25LT1 is AEC-Q101 qualified and PPAP capable per onsemi's datasheet revision 18 (November 2022). It undergoes stress testing for temperature cycling, high-temperature reverse bias, and electrostatic discharge-validating suitability for automotive cabin and powertrain subsystems.

What is the guaranteed DC current gain (h_FE) range for BC817-25LT1?

The BC817-25LT1 guarantees h_FE between 160 and 400 when tested at I_C = 100 mA and V_CE = 1.0 V. This binning distinguishes it from BC817-16LT1 (100–250) and BC817-40LT1 (250–600), enabling precise base resistor selection for saturation-critical designs.

Can BC817-25LT1 be used in linear amplification applications?

Yes, BC817-25LT1 supports linear operation with f_T = 100 MHz and typical output capacitance (C_obo) of 10 pF. Its h_FE stability across I_C = 1–500 mA (per Figure 9) and low noise characteristics make it suitable for audio preamplifiers and sensor signal conditioning where gain accuracy matters.

What is the thermal resistance (R_JA) of BC817-25LT1 on standard PCB?

The BC817-25LT1 exhibits R_JA = 556 °C/W on FR-5 board (1.0 × 0.75 × 0.062 in) at T_A = 25°C. This value assumes minimal copper area; adding 100 mm² of 1 oz copper on both sides reduces R_JA to ~250 °C/W, enabling higher power operation without exceeding +150°C junction limit.

BC817-25LT1 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-236-3, SC-59, SOT-23-3

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 500 mA

Voltage - Collector Emitter Breakdown (Max):: 45 V

Vce Saturation (Max) @ Ib, Ic:: 700mV @ 50mA, 500mA

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

DC Current Gain (hFE) (Min) @ Ic, Vce:: 160 @ 100mA, 1V

Power - Max:: 300 mW

Frequency - Transition:: 100MHz

Operating Temperature:: -

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3 (TO-236)

BC817-25LT1 FAQ

1.How can I place an order for BC817-25LT1 through Aetrix?

Please submit a Request for Quotation (RFQ) for BC817-25LT1 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 BC817-25LT1 reliable?

The price and inventory of BC817-25LT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC817-25LT1 is usually 5 days.

3.What payment methods are accepted for BC817-25LT1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC817-25LT1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC817-25LT1?

BC817-25LT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC817-25LT1 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 BC817-25LT1?

For technical support, including BC817-25LT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC817-25LT1 requirements.

6.How does Aetrix verify that BC817-25LT1 is sourced from the original manufacturer or authorized distributors?

All BC817-25LT1 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 BC817-25LT1 meets industry standards.

7.What is the process for return or replacement of BC817-25LT1?

All BC817-25LT1 units undergo pre-shipment inspection (PSI). If there is an issue with BC817-25LT1, 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 BC817-25LT1 part is unused and in its original packaging.

Return procedure for BC817-25LT1:

1.Submit a request within 90 days.

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

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