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NXP Semiconductors BF245A,112
- Part No.:
- BF245A,112
- Manufacturer:
- NXP Semiconductors
- Category:
- Single FETs, MOSFETs
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
BF245A,112.pdf
- Description:
- RF MOSFET JFET 15V TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:8,387
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Product details
Overview
BF245A,112 from NXP Semiconductors is a general-purpose N-channel symmetrical junction field-effect transistor (JFET) in a plastic TO-92 variant (SOT54) package, rated for ±30 V drain-source voltage, 2–6.5 mA zero-gate-voltage drain current (IDSS), and 700 MHz cut-off frequency (fgfs). It operates with gate-source cut-off voltage (VGSoff) between −0.25 V and −8 V and delivers 3–6.5 mS forward transfer admittance (|yfs|) at 1 kHz - ideal for low-noise HF amplifier stages in radio receivers and signal conditioning circuits.
For engineers reviewing the BF245A,112 datasheet, BF245A,112 pinout, BF245A,112 application, or BF245A,112 equivalent, key selection considerations include its symmetrical drain/source interchangeability, low noise figure (1.5 dB at 100 MHz), TO-92 mechanical compatibility, and specified thermal resistance (250 K/W in free air) for discrete analog front-end design.
Technical Context
The BF245A,112 employs a silicon junction FET structure with symmetrical source/drain terminals, enabling bidirectional signal handling in common-source or common-drain configurations. Its static characteristics are defined at Tj = 25 °C, with pulse-tested dynamic parameters (tp = 300 µs, δ ≤ 0.02) ensuring reliability in RF amplification up to 700 MHz.
It features low reverse transfer capacitance (Crs = 1.1 pF typ at 1 MHz), input capacitance (Cis = 4 pF typ), and output capacitance (Cos = 1.6 pF typ), supporting stable high-frequency gain with minimal Miller effect. The device's noise figure of 1.5 dB at 100 MHz under common-source conditions with RG = 1 kΩ makes it suitable for sensitive receiver front-ends.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VDS | ±30 V - maximum allowable drain-source voltage without breakdown; defines safe operating range in linear and switching applications |
| IDSS | 2–6.5 mA - zero-bias drain current; sets DC bias point and gain capability in amplifier designs |
| VGSoff | −0.25 to −8 V - gate-source cut-off voltage; determines turn-off threshold and channel depletion behavior |
| |yfs| | 3–6.5 mS - forward transfer admittance at 1 kHz; directly relates to small-signal transconductance and voltage gain potential |
| fgfs | 700 MHz - cut-off frequency where transconductance drops to 70% of low-frequency value; confirms usable RF bandwidth |
| F | 1.5 dB - noise figure at 100 MHz; quantifies added noise in low-level signal amplification, critical for receiver sensitivity |
| Ptot | 300 mW - total power dissipation at Tamb ≤ 75 °C; constrains thermal design and continuous output capability |
Pinout & Package
BF245A,112 is housed in a plastic single-ended leaded (through-hole) TO-92 variant package designated SOT54, with 3 leads on-circle and standardized mechanical dimensions per IEC/JEDEC outlines (D = 4.8 mm, E = 4.2 mm, L = 14.5 mm).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | drain (d) | Main current-carrying terminal; interchangeable with source in symmetrical JFET operation |
| 2 | source (s) | Reference terminal for gate control; interchangeable with drain; connects to circuit ground or bias network |
| 3 | gate (g) | High-impedance control electrode; requires ESD protection during handling due to fragile oxide interface |
Key Features
| Feature | Design Value |
|---|---|
| Symmetrical drain/source terminals | Enables flexible circuit topology - same device used in common-source, common-drain, or bidirectional signal paths without redesign |
| 700 MHz cut-off frequency | Supports amplification through HF band (3–30 MHz) and into lower VHF, validated under pulsed 200 MHz test conditions |
| 1.5 dB noise figure at 100 MHz | Minimizes degradation of signal-to-noise ratio in tuned RF preamplifiers and mixer driver stages |
| TO-92 (SOT54) through-hole package | Ensures mechanical robustness and thermal stability on PCBs with ≥3 mm lead length and 10 mm × 10 mm drain pad |
| Low Crs (1.1 pF) and Cos (1.6 pF) | Reduces feedback and instability in high-gain amplifier layouts, easing layout and matching network design |
Applications
| HF Receiver Preamplifier | Audio Signal Buffer |
|---|---|
Use Scenario: Low-noise amplification of weak shortwave signals before mixing in communications receivers. IC Role / Device Role / Timing Role: N-channel JFET configured as common-source amplifier with tuned input network. Use Value: 1.5 dB noise figure and 700 MHz fgfs preserve weak-signal integrity while delivering >15 dB gain at 10–20 MHz. |
Use Scenario: High-input-impedance buffer between high-Z sensor outputs and low-Z audio processing stages. IC Role / Device Role / Timing Role: Source-follower configuration providing unity-gain, low-output-impedance drive. Use Value: Symmetrical d/s terminals simplify layout; 300 mW Ptot supports continuous operation with <100 mW dissipation. |
| DC-Coupled Instrumentation Amplifier Input Stage | LF Oscillator Active Element |
Use Scenario: Precision DC-coupled gain stage in analog test equipment requiring low drift and minimal gate leakage. IC Role / Device Role / Timing Role: JFET used in differential pair or cascode input with fixed VGS bias. Use Value: IGSS ≤ 5 nA at −20 V ensures stable DC operating point; VGSoff tolerance supports matched-pair biasing. |
Use Scenario: Active element in Colpitts or Clapp oscillator circuits generating stable LF to HF signals. IC Role / Device Role / Timing Role: JFET provides variable transconductance for amplitude stabilization and frequency tuning. Use Value: |yfs| tunability across IDSS range enables precise oscillation amplitude control; Crs/Cos values support predictable tank resonance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar N-channel JFET amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| J310 | Higher IDSS (20–60 mA), lower VGSoff (−0.5 to −3.0 V), TO-92 package but different pinout (drain/source/gate = 1/2/3 vs BF245A's d/s/g = 1/2/3) | Better suited for higher-current gain stages; not pin-compatible - requires PCB layout revision | Select when higher transconductance and wider VGSoff range are needed; verify pin mapping before substitution |
| 2N5457 | Lower IDSS (1–5 mA), similar VGSoff (−0.5 to −5.0 V), identical TO-92 pinout (d/s/g = 1/2/3), but lower fgfs (≈150 MHz) | Acceptable for LF/AF amplification only; insufficient for HF applications beyond 30 MHz | Use only in audio or DC-coupled instrumentation where RF performance is not required |
Compared with J310 and 2N5457, BF245A,112 offers balanced IDSS and VGSoff for general-purpose HF amplification, retains full pinout compatibility with other BF245 variants, and delivers verified 700 MHz bandwidth - making it the preferred choice where symmetrical operation and mid-band RF performance are essential.
Availability
BF245A,112 is available at Aetrix Electronics and suitable for HF receiver preamplifiers, audio signal buffers, and DC-coupled instrumentation amplifier input stages requiring stable component supply and long-term obsolescence management.
Supply support for BF245A,112 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
NXP Semiconductors is a global semiconductor company specializing in high-performance mixed-signal and standard products, with leadership in RF, analog, power management, and interface technologies.
The BF245A,112 belongs to NXP's legacy discrete JFET product line designed for general-purpose analog signal conditioning - emphasizing low noise, symmetrical operation, and robust through-hole packaging for industrial, communications, and educational applications.
FAQ
What is the maximum operating junction temperature for BF245A,112?
The BF245A,112 has a maximum operating junction temperature (Tj) of 150 °C, as specified in the Absolute Maximum Ratings table. This limit applies under all operating conditions, and thermal design must ensure junction temperature remains below this value using the given thermal resistance (Rth j-a = 250 K/W in free air) and ambient temperature constraints.
Is BF245A,112 pin-compatible with BF245B or BF245C?
Yes, BF245A,112 shares identical pinout (drain/source/gate = pins 1/2/3), package (SOT54/TO-92 variant), and footprint with BF245B and BF245C. However, electrical parameters differ - notably IDSS (2–6.5 mA for BF245A,112 vs. 6–15 mA for BF245B and 12–25 mA for BF245C) - so direct substitution requires verification of bias and gain requirements in the target circuit.
Does BF245A,112 support bidirectional signal flow?
Yes, BF245A,112 is a symmetrical junction FET with interchangeable drain and source terminals, explicitly stated in the Features section. This allows use in bidirectional analog switches, AC-coupled amplifiers, or circuits where signal polarity reversal is required - provided gate biasing remains appropriate relative to the chosen reference terminal.
What is the gate leakage current specification for BF245A,112?
The gate cut-off current (IGSS) for BF245A,112 is specified as ≤ −5 nA at VGS = −20 V and Tj = 25 °C, rising to ≤ −0.5 µA at Tj = 125 °C. These values reflect the inherent low-leakage nature of silicon junction gates, supporting stable DC biasing in high-impedance amplifier and oscillator applications.
Can BF245A,112 be used in surface-mount designs?
No - BF245A,112 is exclusively offered in the through-hole SOT54 (TO-92 variant) package. It lacks an official surface-mount variant. Designers requiring SMT compatibility must select alternative JFETs such as the SOT-23 packaged MMBFJ310 or similar, which differ electrically and mechanically from BF245A,112.
BF245A,112 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Technology:
- JFET
- Configuration:
- N-Channel
- Frequency:
- 100MHz
- Gain:
- -
- Voltage - Test:
- 15 V
- Current Rating (Amps):
- 6.5mA
- Noise Figure:
- 1.5dB
- Current - Test:
- -
- Power - Output:
- -
- Voltage - Rated:
- 30 V
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
BF245A,112 FAQ
1.How can I place an order for BF245A,112 through Aetrix?
Please submit a Request for Quotation (RFQ) for BF245A,112 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 BF245A,112 reliable?
The price and inventory of BF245A,112 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BF245A,112 is usually 5 days.
3.What payment methods are accepted for BF245A,112?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BF245A,112 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BF245A,112?
BF245A,112 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BF245A,112 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 BF245A,112?
For technical support, including BF245A,112 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BF245A,112 requirements.
6.How does Aetrix verify that BF245A,112 is sourced from the original manufacturer or authorized distributors?
All BF245A,112 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 BF245A,112 meets industry standards.
7.What is the process for return or replacement of BF245A,112?
All BF245A,112 units undergo pre-shipment inspection (PSI). If there is an issue with BF245A,112, 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 BF245A,112 part is unused and in its original packaging.
Return procedure for BF245A,112:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BF245A,112 Tags
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