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onsemi BC849BLT1
- Part No.:
- BC849BLT1
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BC849BLT1.pdf
- Description:
- TRANS NPN 30V 0.1A SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:7,927
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Product details
Overview
BC849BLT1 from onsemi is an NPN general-purpose silicon transistor in SOT-23 package, rated for VCEO = 30 V, IC = 100 mA, and hFE = 200–450 (at IC = 2 mA, VCE = 5 V), with fT = 100 MHz and VCE(sat) ≤ 0.6 V at IC/IB = 100 mA/5 mA - used in low-voltage signal switching and amplification stages of consumer power supplies and sensor interface circuits.
For engineers reviewing the BC849BLT1 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, thermal derating behavior, ESD robustness (HBM >4000 V), SOT-23 terminal mapping, and validated alternative transistors for discrete BJT replacement in cost-sensitive, space-constrained PCB designs.
Technical Context
The BC849BLT1 operates as a medium-gain, medium-speed NPN bipolar junction transistor optimized for linear amplification and saturated switching in ambient temperatures from −55°C to +150°C. Its DC current gain (hFE) is binned to "B" grade (200–450), and its fT of 100 MHz supports audio-frequency and low-MHz digital signal conditioning.
Thermal performance is defined for two board conditions: 225 mW dissipation on FR-5 (RJA = 556°C/W) and 300 mW on alumina substrate (RJA = 417°C/W). Saturation voltage remains ≤0.6 V under 100 mA collector current with 5 mA base drive, enabling efficient low-side switch operation in 3.3 V and 5 V logic-compatible interfaces.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 30 V - Maximum allowable collector-emitter voltage before breakdown; sets safe operating range in 24 V rail monitoring or 3.3/5 V logic-level switching. |
| IC (continuous) | 100 mA - Continuous collector current limit; suitable for driving LEDs, small relays, or MOSFET gates without external heat sinking. |
| hFE (min–max) | 200–450 @ IC = 2 mA, VCE = 5 V - Gain binning ensures predictable bias stability across production lots in amplifier or current mirror designs. |
| fT | 100 MHz - Transition frequency confirms usable bandwidth up to ~10 MHz for small-signal amplification in sensor front-ends. |
| VCE(sat) | ≤0.6 V @ IC = 100 mA, IB = 5 mA - Low saturation voltage minimizes power loss and self-heating in switching applications. |
| ESD HBM | >4000 V - Robust electrostatic discharge immunity simplifies handling and reduces risk of field failure in assembly and end-use environments. |
Pinout & Package
SOT-23 (Case 318, Style 6) surface-mount plastic package with gull-wing leads; 2.0 mm × 1.25 mm footprint, 0.95 mm height, and moisture sensitivity level (MSL) 1 - compatible with standard reflow profiles and automated placement.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base | Control electrode; requires current-limited drive (e.g., via 10 kΩ resistor from 3.3 V logic) to achieve full saturation at IC = 100 mA. |
| 2 | Emitter | Reference node for current flow; connected to ground or low-impedance return path to maintain stable VBE and minimize thermal drift. |
| 3 | Collector | Output node; handles switched load current up to 100 mA; layout must minimize trace inductance when driving capacitive loads. |
Key Features
| Feature | Design Value |
|---|---|
| Pb-free SOT-23 packaging | RoHS-compliant construction with MSL 1 rating enables lead-free reflow without baking or special handling. |
| High hFE bin (B grade) | Guaranteed 200–450 gain range improves consistency in emitter-follower buffers and analog gain stages without trim resistors. |
| Low VCE(sat) | ≤0.6 V at IC/IB = 20 ensures <100 mW power dissipation during switching, reducing thermal stress on adjacent components. |
| 100 MHz fT | Supports stable small-signal amplification up to 10 MHz, meeting requirements for ultrasonic sensor receivers and audio preamps. |
Applications
| LED Driver Circuit | Microcontroller GPIO Expander |
|---|---|
|
Use Scenario: Driving 20 mA indicator LEDs from 3.3 V MCU outputs in industrial HMIs. IC Role / Device Role / Timing Role: Low-side switch controlled by microcontroller GPIO pin. Use Value: VCE(sat) ≤ 0.6 V ensures LED forward voltage drop remains dominant, maximizing brightness control resolution. |
Use Scenario: Extending digital I/O count using discrete transistor arrays in space-constrained IoT sensor nodes. IC Role / Device Role / Timing Role: Digital buffer/inverter stage translating 3.3 V logic to 5 V peripheral interfaces. Use Value: hFE ≥ 200 guarantees reliable saturation with ≤10 µA base current, minimizing MCU port loading. |
| DC-DC Feedback Sensing | Temperature Sensor Interface |
|
Use Scenario: Isolating feedback signals from optocoupler outputs in isolated flyback converters. IC Role / Device Role / Timing Role: Linear amplifier stage conditioning opto-collector current into precise reference voltage. Use Value: Tight hFE binning (200–450) maintains consistent loop gain across temperature, improving regulation accuracy. |
Use Scenario: Amplifying low-level output from NTC thermistors in battery management systems. IC Role / Device Role / Timing Role: Common-emitter amplifier converting resistance change into measurable voltage swing. Use Value: fT = 100 MHz provides ample bandwidth for sub-1 kHz thermal response, avoiding phase lag in closed-loop control. |
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 |
|---|---|---|---|
| BC847BLT1 | VCEO = 45 V (vs. 30 V); hFE = 200–450 same bin; identical SOT-23 package and pinout. | Higher voltage margin suits 24 V input monitoring where BC849BLT1 may approach breakdown limits. | Select BC847BLT1 when system rails exceed 20 V and headroom above VCEO is critical. |
| MMBT3904LT1G | VCEO = 40 V; hFE = 100–300 (lower max gain); fT = 300 MHz; Pb-free SOT-23. | Higher fT supports faster switching but lower gain requires larger base drive current. | Choose MMBT3904LT1G for higher-speed digital switching where gain tolerance is less critical than edge rate. |
Compared with BC849BLT1, BC847BLT1 offers higher voltage safety margin without changing layout or drive strength, while MMBT3904LT1G trades gain consistency for bandwidth - making BC849BLT1 optimal for stable, low-power linear amplification at 30 V-class rails.
Availability
BC849BLT1 is available at Aetrix Electronics and suitable for LED driver circuits, microcontroller GPIO expansion, DC-DC feedback sensing, and temperature sensor interfaces requiring stable component supply, consistent parametric binning, and RoHS-compliant SMT packaging.
Supply support for BC849BLT1 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 management, analog, and discrete devices for automotive, industrial, and cloud infrastructure markets.
The BC849BLT1 belongs to the BC846–BC850 family of general-purpose NPN transistors designed for high-volume, cost-sensitive applications demanding consistent gain, low saturation voltage, and robust manufacturability in SOT-23 packaging.
FAQ
What is the maximum collector-emitter voltage rating for BC849BLT1?
The BC849BLT1 has a maximum collector-emitter voltage (VCEO) rating of 30 V DC. This value is specified under test condition IC = 10 mA and defines the absolute upper limit before avalanche breakdown occurs. Exceeding 30 V risks irreversible device damage, especially at elevated temperatures. Designers should maintain ≥20% derating margin - i.e., limit steady-state VCE to ≤24 V - in reliability-critical BC849BLT1 applications.
What is the guaranteed DC current gain range for BC849BLT1?
The BC849BLT1 is binned to the "B" gain group, guaranteeing hFE between 200 and 450 when measured at IC = 2.0 mA and VCE = 5.0 V. This range is confirmed per the official onsemi datasheet Rev. 6 (June 2004) and applies across the full operating temperature range of −55°C to +150°C. The BC849BLT1's tight hFE distribution supports predictable biasing in amplifier and current-source circuits without manual trimming.
Does BC849BLT1 support lead-free reflow soldering?
Yes, BC849BLT1 is manufactured in a Pb-free SOT-23 package compliant with RoHS Directive 2011/65/EU. It carries moisture sensitivity level (MSL) 1 per J-STD-020, meaning it can be stored indefinitely at ≤30°C/60% RH and subjected to standard lead-free reflow profiles (peak 260°C) without baking. The BC849BLT1 marking "2B" and packaging code confirm its Pb-free status per onsemi's ordering information table.
What is the thermal resistance of BC849BLT1 on FR-5 board?
When mounted on a standard FR-5 PCB (1.0 × 0.75 × 0.062 in), the BC849BLT1 exhibits a junction-to-ambient thermal resistance (RJA) of 556°C/W at TA = 25°C. Its total device dissipation is rated at 225 mW, derating linearly by 1.8 mW/°C above 25°C. This means maximum power dissipation drops to 135 mW at 75°C ambient - a key constraint for BC849BLT1 use in enclosed industrial enclosures without forced airflow.
How does BC849BLT1 compare to BC847BLT1 in terms of voltage ratings?
The BC849BLT1 has VCEO = 30 V and VCBO = 30 V, while the BC847BLT1 specifies VCEO = 45 V and VCBO = 50 V - both share identical hFE binning (200–450), SOT-23 package, and pinout. Therefore, BC847BLT1 provides 15 V higher collector-emitter standoff, making it preferable in 24 V systems where transient spikes could push BC849BLT1 near breakdown. The BC849BLT1 remains optimal where 30 V margin suffices and cost or inventory consolidation favors tighter voltage grading.
BC849BLT1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 100 mA
- Voltage - Collector Emitter Breakdown (Max):
- 30 V
- Vce Saturation (Max) @ Ib, Ic:
- 600mV @ 5mA, 100mA
- Current - Collector Cutoff (Max):
- 15nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 200 @ 2mA, 5V
- Power - Max:
- 300 mW
- Frequency - Transition:
- 100MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3 (TO-236)
BC849BLT1 FAQ
1.How can I place an order for BC849BLT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for BC849BLT1 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 BC849BLT1 reliable?
The price and inventory of BC849BLT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC849BLT1 is usually 5 days.
3.What payment methods are accepted for BC849BLT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC849BLT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC849BLT1?
BC849BLT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC849BLT1 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 BC849BLT1?
For technical support, including BC849BLT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC849BLT1 requirements.
6.How does Aetrix verify that BC849BLT1 is sourced from the original manufacturer or authorized distributors?
All BC849BLT1 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 BC849BLT1 meets industry standards.
7.What is the process for return or replacement of BC849BLT1?
All BC849BLT1 units undergo pre-shipment inspection (PSI). If there is an issue with BC849BLT1, 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 BC849BLT1 part is unused and in its original packaging.
Return procedure for BC849BLT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC849BLT1 Tags
-
MMBT3906LT1G
onsemi
-
MMBT3904-7-F
Diodes Incorporated
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MMBT3904LT1G
onsemi
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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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