NXP Semiconductors BB149A,115

Overview

BB149A,115 from NXP Semiconductors is a UHF variable capacitance diode (varactor) fabricated in planar technology and housed in the SOD323 (SC-76) surface-mount package. It delivers 2.1 pF capacitance at 28 V reverse bias, a Cd(1V)/Cd(28V) ratio of 9, and 2 % gliding matching accuracy via Direct Matching Assembly (DMA), enabling precise tuning in high-frequency oscillator circuits.

For engineers reviewing the BB149A,115 datasheet, BB149A,115 pinout, BB149A,115 application, or BB149A,115 equivalent, key selection criteria include its 470 MHz series resistance (0.6–0.75 Ω), low leakage (≤10 nA at 30 V/25 °C), tight capacitance matching across voltage sweep, and suitability for UHF band tuning where linearity and thermal stability are critical.

Technical Context

The BB149A,115 operates as a reverse-biased junction varactor, with capacitance varying from 18.22–21.26 pF at 1 V to 1.95–2.23 pF at 28 V under 1 MHz test conditions. Its temperature coefficient is characterized across 0–85 °C, and it maintains ≤2 % capacitance matching across sequences of 10 diodes using gliding DMA.

Designed for UHF signal path tuning, it features low series resistance (rs = 0.6–0.75 Ω at 470 MHz) and exhibits reverse current ≤10 nA at VR = 30 V and 25 °C - rising to ≤200 nA at 85 °C - supporting stable VCO performance in thermally demanding environments.

Key Specifications

Pinout & Package

SOD323 (SC-76) plastic surface-mounted package: 2-terminal, 1.35 × 0.80 × 0.45 mm body, cathode marked by bar on top surface.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BB204,115 and SMV1232-011, the BB149A,115 uniquely combines 2 % gliding DMA matching, 9:1 tuning ratio, and sub-0.75 Ω series resistance - making it optimal for UHF VCOs where phase noise, repeatability, and wideband agility are jointly constrained.

Availability

BB149A,115 is available at Aetrix Electronics and suitable for UHF television tuners, voltage-controlled oscillators, FM radio receivers, and electronic tuning filters requiring stable component supply across industrial temperature ranges and long-lifecycle designs.

Supply support for BB149A,115 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 BB149A,115 belongs to NXP's RF varactor diode product line, engineered specifically for high-linearity, high-stability electronic tuning in UHF communication and broadcast systems.

FAQ

What is the primary function of the BB149A,115 in RF circuits?

The BB149A,115 functions as a voltage-controlled variable capacitance diode (varactor), used to tune resonant frequencies in UHF LC tank circuits. Its capacitance changes predictably with applied reverse bias - from ~20 pF at 1 V to 2.1 pF at 28 V - enabling precise frequency control in tuners and VCOs without mechanical components. The BB149A,115 achieves this with low series resistance and tight matching for minimal signal loss and consistent performance.

Does the BB149A,115 support operation across the full industrial temperature range?

Yes, the BB149A,115 is specified for junction temperatures from −55 °C to +125 °C and storage temperatures from −55 °C to +150 °C. Capacitance vs. voltage curves and reverse leakage are characterized from 0 °C to 85 °C, and its temperature coefficient is documented across that range - confirming robust UHF tuning capability in industrial-grade equipment. The BB149A,115 maintains ≤2 % matching stability over thermal cycling when used within rated limits.

How is the 2 % capacitance matching of the BB149A,115 achieved and verified?

The BB149A,115 achieves ≤2 % capacitance matching across sequences of 10 diodes using a Direct Matching Assembly (DMA) process combined with gliding measurement methodology - not batch sorting. This is verified per datasheet Table 5 under "capacitance matching" at VR = 1 V to 28 V. The BB149A,115 does not rely on post-production binning; matching is built into the fabrication and assembly flow for consistent performance in differential or multi-channel tuning applications.

What is the maximum recommended reverse voltage for continuous operation of the BB149A,115?

The absolute maximum reverse voltage (VR) for the BB149A,115 is 30 V, and peak reverse voltage (VRM) is 35 V when used in series with a 10 kΩ resistor. For reliable long-term operation, NXP recommends limiting DC reverse bias to ≤28 V - the voltage at which Cd = 2.1 pF is specified. Exceeding 30 V risks permanent junction damage. The BB149A,115 must remain reverse-biased at all times during operation to avoid forward conduction and nonlinear distortion.

Can the BB149A,115 be used in place of older varactor diodes like BB139 or BB202?

The BB149A,115 is not a direct replacement for BB139 or BB202 due to differences in capacitance range, matching method, and packaging. BB139 offers lower capacitance (≈5–0.5 pF) and no DMA matching; BB202 has higher rs and different C-V slope. While functional in some UHF tuning roles, substituting BB149A,115 requires verifying layout compatibility (SOD323 footprint), bias network impedance, and system-level linearity. The BB149A,115 delivers superior matching and lower rs - but only if the design accommodates its specific 18–2 pF range and 2 % DMA behavior.