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Home > Products > Discrete Semiconductor Products > Diodes > Variable Capacitance (Varicaps, Varactors)

Diodes Incorporated BBY40TA

Name: BBY40TA
Brand: Diodes Incorporated
SKU: BBY40TA
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BBY40TA

Manufacturer:: Diodes Incorporated

Category:: Variable Capacitance (Varicaps, Varactors)

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

Datasheet:: BBY40TA.pdf

Description:: DIODE VARI CAP 28V 330MW SOT23-3

Quantity:: RFQ Add To RFQ list

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Inventory:18,348

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Product details

Overview

BBY40TA from NXP Semiconductors is a silicon planar variable capacitance diode (varactor) in SOT23 package, rated for 28 V reverse breakdown voltage, 4.3–6.0 pF capacitance at 25 V, and 26–32 pF at 3 V, with a capacitance ratio of 5.0–6.5 (3 V/25 V), used in VHF/UHF tuning circuits for FM radio front-ends and local oscillator matching networks.

For engineers reviewing the BBY40TA datasheet, BBY40TA pinout, BBY40TA application, or BBY40TA equivalent, key selection criteria include reverse voltage rating, capacitance range at specified bias points, capacitance ratio linearity, series resistance at RF frequencies, and thermal stability across −55°C to +150°C operation.

Technical Context

The BBY40TA operates as a voltage-controlled capacitor where junction capacitance varies inversely with applied reverse bias. Its planar silicon structure ensures stable C-V characteristics and low series resistance (0.4–0.6 Ω at 200 MHz), optimized for high-frequency tuning up to 1 GHz.

Capacitance is specified at 1 MHz under controlled thermal conditions (T_amb = 25°C), with guaranteed minimum breakdown voltage of 28 V and leakage current ≤10 nA at 28 V, supporting reliable operation in battery-powered and automotive-grade RF modules.

Key Specifications

Parameter	Value and Actual Design Meaning
V_BR	28.0 V minimum reverse breakdown voltage - sets maximum usable tuning voltage in oscillator tank circuits
C_d @ 3 V	26.0–32.0 pF - defines low-voltage capacitance ceiling for wide-range frequency coverage
C_d @ 25 V	4.3–6.0 pF - establishes high-bias capacitance floor for VHF band tuning
C_d Ratio	5.0–6.5 (3 V/25 V) - quantifies usable tuning range linearity for PLL loop stability
r_d	0.4–0.6 Ω at 200 MHz - limits Q-factor degradation in resonant tank applications
P_tot	330 mW at T_amb = 25°C - constrains power handling in continuous RF bias environments

Pinout & Package

SOT23 plastic surface-mount package with gull-wing leads; standardized 3-pin outline per JEDEC TO-236AB.

Pin/Terminal	Circuit Role	Design Meaning
1	Anode	DC bias input terminal; connected to ground or low-impedance AC return in tuning networks
2	Cathode	RF signal node; connects to inductor or resonator in parallel-tuned VCO tanks
3	Anode (internally tied to Pin 1)	Redundant anode connection for mechanical robustness and thermal relief in PCB layout

Key Features

Feature	Design Value
High capacitance ratio	6.5:1 (3 V/25 V) enables wide frequency sweep without switching capacitors
Low series resistance	0.4 Ω typical at 200 MHz preserves tank circuit Q > 100 at 100 MHz
Stable C–V curve	Planar junction ensures repeatable capacitance vs. voltage response across production lots
Extended temperature range	−55°C to +150°C operation supports under-hood automotive tuner modules

Applications

FM Radio Tuner Front-End

VHF Local Oscillator Matching

Use Scenario: Tuning of RF input filters and image-reject stages in portable FM receivers.

IC Role / Device Role / Timing Role: Voltage-controlled reactance element in parallel LC tank, adjusted by microcontroller DAC output.

Use Value: 6.5:1 capacitance ratio allows full 87.5–108 MHz coverage with single inductor and no switched capacitor banks.

Use Scenario: Frequency calibration of VHF local oscillators in two-way radios and ISM-band transceivers.

IC Role / Device Role / Timing Role: Bias-dependent capacitor in Colpitts oscillator feedback path, enabling ±500 kHz pull range.

Use Value: 0.4 Ω series resistance maintains oscillator phase noise below −110 dBc/Hz at 10 kHz offset.

Automotive Keyless Entry Transmitter

UHF RFID Reader Matching Network

Use Scenario: Antenna impedance matching and carrier frequency trimming in 315/433 MHz TPMS transmitters.

IC Role / Device Role / Timing Role: Fine-tuning capacitor in π-network between PA output and antenna feed point.

Use Value: Stable C–V behavior over −40°C to +105°C ensures consistent radiated power across vehicle operating conditions.

Use Scenario: Dynamic load compensation in 860–960 MHz UHF RFID reader antenna couplers.

IC Role / Device Role / Timing Role: Adjustable shunt capacitance in directional coupler bias network for forward power stabilization.

Use Value: 28 V breakdown rating accommodates transient voltage spikes during ESD events on reader ports.

Equivalent & Alternatives

The following parts are listed as comparable options for similar varactor diode applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
BBY52	Higher C_d @ 3 V (35–42 pF), lower C_d ratio (4.0–5.0), same SOT23 package	Better suited for lower-frequency (30–300 MHz) tuning where wider low-voltage capacitance is prioritized over ratio	Select BBY52 when target frequency range falls below 200 MHz and higher initial capacitance eases inductor sizing.
SMV1232-011	0.35 Ω r_d, 25 V V_BR, 2.5–25 pF range, SC-70 package	Optimized for 2.4 GHz WiFi/BT front-ends; smaller footprint but lower voltage margin	Choose SMV1232-011 only for 2.4 GHz designs requiring sub-0.4 Ω loss and space-constrained layouts.

Compared with BBY40TA, BBY52 offers greater low-bias capacitance but reduced tuning ratio, while SMV1232-011 delivers lower RF loss at higher frequencies but sacrifices 3 V headroom and requires re-layout for SC-70.

Availability

BBY40TA is available at Aetrix Electronics and suitable for FM radio tuners, VHF oscillator calibration, automotive keyless entry systems, and UHF RFID reader matching networks requiring stable component supply across extended temperature ranges.

Supply support for BBY40TA 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 headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and consumer applications.

The BBY40TA belongs to NXP's RF varactor diode product line, engineered specifically for high-linearity voltage-controlled tuning in VHF/UHF communication systems with stringent thermal and reliability requirements.

FAQ

What is the maximum recommended reverse voltage for continuous operation of BBY40TA?

The absolute maximum reverse voltage is 28 V, defined at I_R = 10 µA. For reliable long-term operation, design bias should remain ≤25 V to maintain margin against process variation and temperature drift, especially above 85°C ambient.

Does BBY40TA require external DC blocking when used in RF tank circuits?

Yes - a series DC-blocking capacitor (typically 100 pF ceramic) must isolate the RF signal path from the DC bias network. The diode's anode and cathode are not RF-isolated internally; direct RF injection into the bias line causes signal leakage and distortion.

Can BBY40TA be substituted with BBY40 without impact on performance?

BBY40TA is the tape-and-reel packaging variant of BBY40; electrical and thermal specifications are identical. The "TA" suffix denotes packaging format only - no parameter differences exist between BBY40 and BBY40TA devices.

Is SPICE model data publicly available for BBY40TA?

SPICE parameter data is available directly from NXP upon formal request using their support portal; no public model is hosted on distributor sites or NXP's general download pages. Model includes junction capacitance, series resistance, and leakage current dependencies on voltage and temperature.

BBY40TA Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: *

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

Packaging:: Tape & Reel (TR)

Product Status:: Discontinued at Digi-Key

Capacitance @ Vr, F:: 6pF @ 25V, 1MHz

Capacitance Ratio:: 6.5

Capacitance Ratio Condition:: C3/C25

Voltage - Peak Reverse (Max):: 28 V

Diode Type:: Single

Q @ Vr, F:: -

Operating Temperature:: -55°C ~ 150°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

BBY40TA FAQ

1.How can I place an order for BBY40TA through Aetrix?

Please submit a Request for Quotation (RFQ) for BBY40TA 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 BBY40TA reliable?

The price and inventory of BBY40TA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BBY40TA is usually 5 days.

3.What payment methods are accepted for BBY40TA?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BBY40TA transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BBY40TA?

BBY40TA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BBY40TA 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 BBY40TA?

For technical support, including BBY40TA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BBY40TA requirements.

6.How does Aetrix verify that BBY40TA is sourced from the original manufacturer or authorized distributors?

All BBY40TA 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 BBY40TA meets industry standards.

7.What is the process for return or replacement of BBY40TA?

All BBY40TA units undergo pre-shipment inspection (PSI). If there is an issue with BBY40TA, 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 BBY40TA part is unused and in its original packaging.

Return procedure for BBY40TA:

1.Submit a request within 90 days.

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

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