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onsemi BC849BMTF
- Part No.:
- BC849BMTF
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BC849BMTF.pdf
- Description:
- TRANS NPN 30V 0.1A SOT-23-3
- Quantity:
- Payment:
- Shipping:
Inventory:5,839
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Product details
Overview
BC849BMTF from Fairchild Semiconductor is an NPN epitaxial silicon transistor in SOT-23 package, rated for 30 V VCEO, 100 mA IC, and 310 mW PC, with hFE = 200–450 (Class B), 1.2 dB noise figure at 1 kHz, and 300 MHz fT. It serves as a low-noise amplifier or general-purpose switch in signal conditioning stages of portable audio and sensor interface circuits.
For engineers reviewing the BC849BMTF datasheet, pinout, applications, or equivalent options, key selection criteria include its Class B hFE range, low-noise performance versus BC846/847 variants, SOT-23 footprint compatibility, and suitability for 3.3 V/5 V biasing in compact analog front-ends.
Technical Context
The BC849BMTF operates as a discrete NPN bipolar junction transistor optimized for low-noise amplification and medium-speed switching. Its 1.2 dB noise figure at 1 kHz (RG = 2 kΩ) and 300 MHz fT support audio preamplifier and RF detector roles where signal integrity is critical.
It shares the SOT-23 package and pinout (1: Base, 2: Emitter, 3: Collector) with the BC846–BC850 family, but differs from BC846/847 by lower VCEO/VCBO (30 V / 30 V) and superior noise performance-distinct from BC850's 30–15,000 Hz noise spec.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 30 V - Maximum collector-emitter voltage before breakdown; defines safe operating range in 3.3 V/5 V supply rails. |
| hFE (Class B) | 200–450 - DC current gain range at VCE = 5 V, IC = 2 mA; enables predictable biasing in linear amplifier designs. |
| NF (1 kHz) | 1.2 dB - Noise figure at VCE = 5 V, IC = 200 μA, RG = 2 kΩ; qualifies BC849BMTF for low-noise preamp stages. |
| fT | 300 MHz - Current gain bandwidth product at VCE = 5 V, IC = 10 mA; supports small-signal amplification up to VHF band. |
| VCE(sat) | 250 mV max at IC = 100 mA, IB = 5 mA - Low saturation voltage ensures efficient switching in logic-level driver applications. |
| PC | 310 mW - Maximum power dissipation at TA = 25°C; determines thermal derating requirements on PCBs without heatsinking. |
Pinout & Package
SOT-23 surface-mount package with 3-pin configuration, JEDEC TO-236AB outline, 1.3 mm × 2.9 mm footprint, and 1.1 mm height. Compatible with automated pick-and-place and reflow soldering.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Base) | Control input terminal | Receives base current to modulate collector current; requires current-limiting resistor in digital switch or emitter-follower bias networks. |
| 2 (Emitter) | Current return path | Connected to ground or reference node; establishes common-emitter or common-collector topology depending on collector load placement. |
| 3 (Collector) | Output current terminal | Delivers amplified or switched current to load; must be decoupled when used in RF amplifiers to prevent oscillation. |
Key Features
| Feature | Design Value |
|---|---|
| Low-noise operation | 1.2 dB NF at 1 kHz enables high-SNR audio preamplification without external noise filtering. |
| Class B hFE binning | 200–450 gain range ensures consistent DC bias stability across production lots in amplifier feedback networks. |
| High fT | 300 MHz bandwidth supports wideband signal amplification in IF stages and low-power RF detectors. |
| SOT-23 tape-and-reel packaging | 3000-unit reels enable automated assembly for high-volume consumer electronics manufacturing. |
Applications
| Portable Audio Preamp | Temperature Sensor Interface |
|---|---|
|
Use Scenario: Amplifying microvolt-level output from electret condenser microphones in Bluetooth headsets. IC Role / Device Role / Timing Role: NPN small-signal amplifier in common-emitter configuration with emitter degeneration. Use Value: 1.2 dB noise figure preserves SNR; 300 MHz fT accommodates ultrasonic cancellation harmonics up to 20 kHz. |
Use Scenario: Buffering and gain-setting for analog output of thermistor-based temperature sensing circuits. IC Role / Device Role / Timing Role: Linear amplifier with fixed-gain bias network feeding ADC input. Use Value: Tight hFE binning (200–450) minimizes calibration drift; 30 V VCEO allows operation across 3.3 V–5 V supply variations. |
| LED Driver Switch | RS-232 Level Shifter |
|
Use Scenario: Driving 20 mA indicator LEDs from 3.3 V GPIO pins in industrial HMI panels. IC Role / Device Role / Timing Role: Saturated switch with base resistor limiting IB to ensure IC/IB ≥ 20. Use Value: 250 mV VCE(sat) at 100 mA reduces power loss; SOT-23 footprint saves board space vs. SO-8 alternatives. |
Use Scenario: Converting 0–3.3 V logic levels to ±12 V RS-232 compliant signals in embedded serial gateways. IC Role / Device Role / Timing Role: Inverter stage in discrete level-shifting circuit with dual-transistor push-pull output. Use Value: 30 V VCBO withstands RS-232 negative transients; fast switching supports 115.2 kbps baud rates. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN small-signal transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC849CMTF | Higher hFE range (420–800); identical noise, voltage, and frequency specs. | Better suited for high-gain, low-bias-current amplifier stages where gain stability dominates over power efficiency. | Select BC849CMTF when precise high-gain biasing is required; BC849BMTF preferred for moderate-gain, lower-thermal-drift designs. |
| MMBT3904LT1G | Lower VCEO (40 V), higher IC (200 mA), no guaranteed noise spec; hFE = 100–300 (unbinned). | More robust for higher-current switching but lacks verified low-noise performance for sensitive analog front-ends. | Choose MMBT3904LT1G for cost-sensitive digital switching; retain BC849BMTF where 1.2 dB NF and binned hFE are mandatory. |
Compared with BC849CMTF and MMBT3904LT1G, the BC849BMTF delivers optimal balance of verified low-noise operation, production-grade hFE consistency, and SOT-23 manufacturability-making it the preferred choice for audio and precision analog signal paths where noise and gain predictability are design-critical.
Availability
BC849BMTF is available at Aetrix Electronics and suitable for portable audio preamplifiers, temperature sensor interfaces, and LED driver switches requiring stable component supply and long-term production continuity.
Supply support for BC849BMTF 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
Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete ICs before its acquisition by ON Semiconductor in 2016. Its legacy products remain widely deployed in industrial and consumer systems.
The BC849BMTF belongs to Fairchild's BC846–BC850 family of general-purpose NPN transistors designed for low-noise amplification and reliable switching in space-constrained, cost-sensitive applications.
FAQ
What is the hFE range for BC849BMTF?
The BC849BMTF has a guaranteed DC current gain (hFE) range of 200 to 450 at VCE = 5 V and IC = 2 mA, per Fairchild's hFE classification "B" marking (8DB). This binning ensures predictable bias point stability in amplifier and switch designs without requiring post-production gain trimming. The BC849BMTF's hFE is confirmed in the official BC846–BC850 Rev. B1 datasheet, Table "hFE Classification".
Does BC849BMTF have a specified noise figure?
Yes, the BC849BMTF has a specified noise figure of 1.2 dB at VCE = 5 V, IC = 200 μA, RG = 2 kΩ, and f = 1 kHz. This value is explicitly listed in the "Electrical Characteristics" table under "NF" for BC849/BC850 variants. It distinguishes BC849BMTF from BC846/847 (2 dB NF) and confirms its suitability for low-noise analog signal amplification.
What is the maximum collector-emitter voltage rating for BC849BMTF?
The BC849BMTF has a maximum collector-emitter voltage (VCEO) rating of 30 V, as stated in the "Absolute Maximum Ratings" table for BC848/849 variants. This rating applies under DC conditions at TA = 25°C and defines the upper limit for safe operation in common-emitter configurations. Exceeding 30 V risks avalanche breakdown and permanent device damage.
Is BC849BMTF pin-compatible with other transistors in the BC846–BC850 series?
Yes, the BC849BMTF uses the standard SOT-23 package with pin 1 = Base, pin 2 = Emitter, pin 3 = Collector-identical to all BC846–BC850 variants including BC846BMTF and BC850BMTF. This uniform pinout allows direct substitution within the family when voltage, gain, and noise requirements align, though VCEO and NF differ across subtypes.
What is the package type and packing method for BC849BMTF?
The BC849BMTF is supplied in the SOT-23 surface-mount package and shipped in tape-and-reel format with 3000 units per reel. The "MTF" suffix in the part number explicitly denotes tape-and-reel packing, while "M" indicates SOT-23. This configuration supports automated assembly and is documented in the "Ordering Information" section of the BC846–BC850 datasheet.
BC849BMTF 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:
- 310 mW
- Frequency - Transition:
- 300MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
BC849BMTF FAQ
1.How can I place an order for BC849BMTF through Aetrix?
Please submit a Request for Quotation (RFQ) for BC849BMTF 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 BC849BMTF reliable?
The price and inventory of BC849BMTF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC849BMTF is usually 5 days.
3.What payment methods are accepted for BC849BMTF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC849BMTF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC849BMTF?
BC849BMTF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC849BMTF 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 BC849BMTF?
For technical support, including BC849BMTF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC849BMTF requirements.
6.How does Aetrix verify that BC849BMTF is sourced from the original manufacturer or authorized distributors?
All BC849BMTF 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 BC849BMTF meets industry standards.
7.What is the process for return or replacement of BC849BMTF?
All BC849BMTF units undergo pre-shipment inspection (PSI). If there is an issue with BC849BMTF, 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 BC849BMTF part is unused and in its original packaging.
Return procedure for BC849BMTF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC849BMTF Tags
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