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onsemi BC850AMTF
- Part No.:
- BC850AMTF
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BC850AMTF.pdf
- Description:
- TRANS NPN 45V 0.1A SOT-23-3
- Quantity:
- Payment:
- Shipping:
Inventory:30,000
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Product details
Overview
BC850AMTF from onsemi is an NPN epitaxial silicon transistor in SOT-23 package, optimized for low-noise amplifier applications with hFE 110–220, VCEO = 45 V, IC = 100 mA, and noise figure of 1.4–3.0 dB (30–15 kHz). It serves as a precision small-signal gain stage in audio preamplifiers, sensor front-ends, and RF bias networks.
For engineers reviewing the BC850AMTF datasheet, pinout, applications, or equivalent options, key selection criteria include its low-noise performance at 200 µA bias, SOT-23 thermal resistance (RθJA = 403 °C/W), VBE(on) tolerance (580–700 mV), and compatibility with automated thin-film assembly processes.
Technical Context
This device operates as a general-purpose NPN bipolar junction transistor with epitaxial base construction for improved high-frequency response and stable DC gain. Its fT = 300 MHz at VCE = 5 V, IC = 10 mA confirms suitability for VHF amplification and switching up to ~100 MHz.
The BC850AMTF is specifically characterized for low-noise operation across 30–15,000 Hz, distinguishing it from BC846/BC847/BC848 variants. Its VEBO = 5 V and VCBO = 50 V define safe operating limits for signal swing in grounded-emitter configurations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 45 V - Maximum collector-emitter voltage before breakdown; sets headroom for 3.3 V/5 V rail amplifier stages. |
| IC | 100 mA - Continuous DC collector current rating; supports medium-gain active loads without thermal derating below 100°C ambient. |
| hFE | 110–220 - DC current gain range at 2 mA collector current; enables predictable biasing in Class-A small-signal amplifiers. |
| Noise Figure | 1.4–3.0 dB (30–15 kHz) - Quantified low-noise performance critical for microphone preamps and instrumentation front-ends. |
| fT | 300 MHz - Current gain-bandwidth product; validates usable gain at VHF frequencies with proper layout and decoupling. |
| VBE(on) | 580–700 mV @ IC = 2 mA - Base-emitter turn-on voltage spread; informs emitter resistor selection for stable quiescent current. |
| PD | 310 mW - Maximum power dissipation at 25°C; requires thermal derating above ambient (2.48 mW/°C) for sustained operation. |
Pinout & Package
SOT-23 3-lead plastic surface-mount package with standard footprint (2.9 mm × 1.3 mm × 1.0 mm), rated for reflow soldering per J-STD-020. Pin 1 = Base, Pin 2 = Emitter, Pin 3 = Collector.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Base) | Control input | Receives forward-biased current to modulate collector current; requires series resistor for stable bias in common-emitter configuration. |
| 2 (Emitter) | Current return path | Connected to ground or emitter degeneration resistor; establishes reference for VBE and sets transconductance. |
| 3 (Collector) | Output terminal | Delivers amplified current to load or next stage; polarity-sensitive for correct DC biasing in active region operation. |
Key Features
| Feature | Design Value |
|---|---|
| Low-noise amplifier grade | Specified noise figure (1.4–3.0 dB) over 30–15 kHz band - enables high-SNR analog signal conditioning without external filtering. |
| Automated assembly compatible | SOT-23 package with tape-and-reel (TF) packing - supports high-speed pick-and-place for volume production of consumer and industrial PCBs. |
| Complementary PNP pairing | Designed as NPN counterpart to BC856/BC857/BC858 family - allows matched push-pull or differential pair implementation. |
| Epitaxial base structure | Enables fT = 300 MHz and tight hFE distribution - improves frequency response consistency and reduces gain variation across temperature. |
Applications
| Audio Preamp Stage | Sensor Signal Conditioning |
|---|---|
Use Scenario: Low-level microphone or piezoelectric sensor output amplification prior to ADC sampling. IC Role / Device Role / Timing Role: Small-signal NPN amplifier in common-emitter configuration with emitter degeneration. Use Value: 1.4–3.0 dB noise figure ensures minimal SNR degradation at 200 µA bias, preserving weak signal integrity. | Use Scenario: Amplifying millivolt-level outputs from thermistors, strain gauges, or photodiodes in portable instrumentation. IC Role / Device Role / Timing Role: DC-coupled gain block with stable hFE (110–220) enabling predictable gain calibration. Use Value: Tight VBE(on) (580–700 mV) simplifies bias network design for low-drift, battery-powered front-ends. |
| RF Bias Network | Switching Load Driver |
Use Scenario: Providing stable DC bias current to GaAs FETs or MMICs in 100–300 MHz receiver modules. IC Role / Device Role / Timing Role: Constant-current source using emitter-follower configuration with Zener reference. Use Value: fT = 300 MHz ensures minimal phase shift and impedance mismatch in bias feed networks. | Use Scenario: Driving LED indicators, relays, or logic-level MOSFET gates in microcontroller I/O expansion circuits. IC Role / Device Role / Timing Role: Saturated switch with VCE(sat) ≤ 250 mV @ 10 mA/0.5 mA drive. Use Value: Low saturation voltage minimizes power loss and self-heating during continuous ON-state operation. |
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 |
|---|---|---|---|
| BC847AMTF | VCEO = 45 V (same), but higher noise figure (2.0–10.0 dB); hFE 110–220 (same class A), fT = 300 MHz (same). | Less suitable for ultra-low-noise audio/sensor front-ends; acceptable for general-purpose switching and mid-gain amplification. | Select BC847AMTF when noise performance is secondary to cost or availability; verify noise margin in final circuit. |
| MMBT3904LT1G | VCEO = 40 V (5 V lower), hFE 100–300 (broader spread), noise figure not specified; fT = 300 MHz (same). | Not characterized for low-noise operation; widely used in digital logic interfacing and non-critical analog functions. | Choose MMBT3904LT1G for cost-sensitive, non-audio applications where noise is unmonitored and VCEO margin ≥5 V suffices. |
Compared with BC847AMTF and MMBT3904LT1G, the BC850AMTF provides verified low-noise performance (1.4–3.0 dB) essential for precision analog signal chains, while maintaining identical pinout, package, and basic DC parameters - making it the preferred choice when noise-limited design constraints apply.
Availability
BC850AMTF is available at Aetrix Electronics and suitable for audio preamplifiers, sensor signal conditioners, and RF bias networks requiring stable component supply, consistent hFE grading, and low-noise transistor performance across production batches.
Supply support for BC850AMTF 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 manufacturer specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The BC850AMTF belongs to onsemi's legacy general-purpose bipolar transistor product line, designed specifically for low-noise, high-fidelity analog signal amplification and reliable automated assembly in space-constrained SMT applications.
FAQ
What is the maximum collector-emitter voltage rating for BC850AMTF?
The BC850AMTF has a maximum collector-emitter voltage (VCEO) rating of 45 V at TA = 25°C. This rating defines the upper limit for DC voltage applied between collector and emitter while keeping the base open. Exceeding this value risks avalanche breakdown and permanent device damage. Derating is required at elevated ambient temperatures per the datasheet thermal characteristics.
Does BC850AMTF have a specified noise figure, and under what conditions?
Yes, the BC850AMTF has a specified noise figure of 1.4–3.0 dB, measured at VCE = 5 V, IC = 200 µA, RG = 2 kΩ, and frequency range 30–15,000 Hz. This distinguishes it from BC846/BC847/BC848 variants and confirms its suitability for low-noise small-signal amplification tasks where signal integrity is critical.
What does the "A" and "M" suffix in BC850AMTF indicate?
The "A" in BC850AMTF denotes hFE classification A (110–220), while "M" specifies the SOT-23 package. The "TF" suffix indicates tape-and-reel packaging for automated assembly. Together, BC850AMTF identifies a low-noise NPN transistor in SOT-23 format, graded for mid-range DC current gain, and supplied in machine-ready reels.
Can BC850AMTF be used as a direct replacement for BC847AMTF in existing designs?
BC850AMTF shares identical SOT-23 pinout, package dimensions, and basic electrical ratings (VCEO, IC, hFE class A) with BC847AMTF, but offers superior low-noise performance (1.4–3.0 dB vs. 2.0–10.0 dB). It can be substituted in most circuits, though designers should verify noise sensitivity and ensure no unintended interaction with surrounding passive components due to tighter parameter tolerances.
What is the thermal resistance (RθJA) of BC850AMTF, and how does it affect PCB layout?
The BC850AMTF has a junction-to-ambient thermal resistance (RθJA) of 403 °C/W under standard FR-4 PCB conditions (76 mm × 114 mm, minimum land pattern). This high value means even modest power dissipation (e.g., 100 mW) raises junction temperature significantly. Layout best practices include maximizing copper area around the SOT-23 pads and avoiding dense component placement near the device to maintain reliability and parametric stability.
BC850AMTF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Bulk
- Product Status:
- Active
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 100 mA
- Voltage - Collector Emitter Breakdown (Max):
- 45 V
- Vce Saturation (Max) @ Ib, Ic:
- 600mV @ 5mA, 100mA
- Current - Collector Cutoff (Max):
- 15nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 110 @ 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
BC850AMTF FAQ
1.How can I place an order for BC850AMTF through Aetrix?
Please submit a Request for Quotation (RFQ) for BC850AMTF 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 BC850AMTF reliable?
The price and inventory of BC850AMTF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC850AMTF is usually 5 days.
3.What payment methods are accepted for BC850AMTF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC850AMTF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC850AMTF?
BC850AMTF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC850AMTF 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 BC850AMTF?
For technical support, including BC850AMTF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC850AMTF requirements.
6.How does Aetrix verify that BC850AMTF is sourced from the original manufacturer or authorized distributors?
All BC850AMTF 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 BC850AMTF meets industry standards.
7.What is the process for return or replacement of BC850AMTF?
All BC850AMTF units undergo pre-shipment inspection (PSI). If there is an issue with BC850AMTF, 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 BC850AMTF part is unused and in its original packaging.
Return procedure for BC850AMTF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC850AMTF 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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