NXP Semiconductors BB179,315

Overview

BB179,315 from NXP Semiconductors is a planar variable capacitance diode (varactor) designed for UHF tuning applications, featuring 2.1 pF capacitance at 28 V reverse bias, 9:1 capacitance ratio (1 V to 28 V), and 0.6–0.75 Ω series resistance at 470 MHz. It operates in electronic tuning circuits for UHF television tuners and voltage-controlled oscillators (VCOs), where precise capacitance control under reverse bias is critical.

For engineers reviewing the BB179,315 datasheet, BB179,315 pinout, BB179,315 application, or BB179,315 equivalent, this page delivers verified electrical parameters, SOD523 package dimensions, cathode/anode terminal mapping, matching tolerance (≤2 % gliding DMA), and real-world VCO/UHF tuner implementation context - all confirmed from NXP's official product data sheet Rev. 3 (2011).

Technical Context

The BB179,315 functions as a reverse-biased junction varactor, where applied DC voltage modulates depletion-layer width and thus junction capacitance. Its Cd(VR) curve is characterized from 1 V to 28 V with typical values of 19.7 pF at 1 V and 2.1 pF at 28 V, yielding a nominal 9:1 tuning range.

It employs Direct Matching Assembly (DMA) for tight capacitance matching across diode pairs or sequences - ≤2 % variation over 1–28 V range - enabling stable differential tuning in balanced oscillator topologies. The device exhibits low temperature coefficient of capacitance and maintains IR ≤10 nA at VR = 30 V and Tj = 25 °C.

Key Specifications

Pinout & Package

Package: SOD523 (SC-79), ultra-small plastic surface-mount package with 2 leads; overall dimensions 1.25 × 0.85 × 0.65 mm (L × W × H); cathode indicated by marking bar.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BB204,315 and SMV1232-011, the BB179,315 uniquely balances 9:1 tuning ratio, 2 % DMA matching, and sub-0.8 Ω series resistance in the smallest SOD523 footprint - making it the preferred choice for production-grade UHF TV tuners and matched-pair VCOs where ratio, repeatability, and size are jointly constrained.

Availability

BB179,315 is available at Aetrix Electronics and suitable for UHF television tuners, voltage-controlled oscillators (VCOs), RF front-end impedance matching networks, and frequency synthesizer tuning banks requiring stable component supply, tight parametric consistency, and long-term obsolescence management.

Supply support for BB179,315 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 BB179,315 belongs to NXP's legacy RF varactor diode product line, engineered specifically for high-linearity, high-matching UHF tuning in broadcast and wireless infrastructure - emphasizing manufacturable precision over general-purpose use.

FAQ

What is the primary function of the BB179,315 in RF circuits?

The BB179,315 functions as a voltage-controlled variable capacitance diode (varactor), where reverse bias voltage modulates its junction capacitance. In RF circuits, it serves as the tuning element in UHF television tuners and voltage-controlled oscillators (VCOs), enabling precise frequency adjustment via analog control voltage. Its 9:1 capacitance ratio and 2 % DMA matching make BB179,315 especially effective in stable, repeatable UHF band synthesis.

What package type does the BB179,315 use, and how is polarity identified?

The BB179,315 uses the SOD523 (SC-79) ultra-small plastic surface-mount package, measuring 1.25 × 0.85 × 0.65 mm. Polarity is identified by a marking bar on the device body, which designates Pin 1 as the cathode. Pin 2 is the anode. This compact two-terminal configuration ensures minimal parasitic effects in high-frequency layouts where BB179,315 is deployed.

What is the maximum reverse voltage rating for the BB179,315, and why does it matter?

The BB179,315 has a maximum continuous reverse voltage (VR) rating of 30 V and a peak reverse voltage (VRM) of 35 V. This rating defines the upper limit of tuning voltage that can be safely applied without risking junction breakdown. Exceeding 30 V risks irreversible damage, so BB179,315 designs must ensure bias networks remain within this limit - especially important in PLL-based VCOs where control voltage may swing widely.

How does the 2 % DMA matching specification benefit circuit designers using BB179,315?

The ≤2 % capacitance matching (gliding DMA) across a sequence of BB179,315 diodes ensures highly consistent tuning behavior between paired units in differential or push-pull VCO topologies. This reduces frequency offset, improves phase balance, and simplifies factory calibration - directly enhancing yield and performance repeatability in mass-produced UHF tuners where BB179,315 is deployed in matched configurations.

Can the BB179,315 be used in automotive applications?

No - the BB179,315 is not automotive-qualified. Per NXP's official documentation, it is not tested or warranted for automotive use, including under AEC-Q200 stress conditions. Its specified operating junction temperature range is −55 °C to +125 °C, but reliability validation excludes automotive qualification. For automotive-grade varactors, designers must select explicitly qualified alternatives; BB179,315 remains intended for industrial, broadcast, and consumer UHF equipment.