NXP Semiconductors BB187,135

Overview

BB187 from NXP Semiconductors is a planar technology variable capacitance diode (varactor) in an ultra-small SOD523 (SC-79) surface-mount package, designed for VHF tuning applications. It delivers Cd(2V) = 29.3–34.2 pF, Cd(25V) = 2.57–2.92 pF, capacitance ratio ≥11, series resistance ≤0.75 Ω at 470 MHz, and matching accuracy ≤2 % via Direct Matching Assembly (DMA).

For engineers reviewing the BB187 datasheet, BB187 pinout, BB187 application, or BB187 equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin roles, application-specific implementation value, and two confirmed alternative varactors for VHF tuning circuits requiring high linearity and tight capacitance matching.

Technical Context

The BB187 operates as a reverse-biased junction varactor, where capacitance varies nonlinearly with applied DC voltage - optimized for stable, low-loss tuning in VHF band oscillators and filters. Its planar silicon structure enables precise doping control, supporting both high linearity (low C-V curvature) and repeatable DMA matching across production lots.

Designed for RF signal path integration, it exhibits low series resistance (≤0.75 Ω @ 470 MHz, VR = 5 V) and minimal temperature coefficient of capacitance (see Figure 3), enabling predictable oscillator center frequency stability across –55 °C to +125 °C junction temperature range.

Key Specifications

Pinout & Package

SOD523 (SC-79) plastic surface-mounted package: 1.25 × 0.85 mm footprint, 0.65 mm height, 2-terminal configuration with cathode marked by bar.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BB187, BBY52,115 offers greater absolute capacitance but sacrifices tuning ratio and package size, while SMV1232-011 improves ratio and matching at the cost of reduced low-VHF linearity and higher bias voltage requirements - making BB187 optimal for cost-sensitive, size-constrained VHF TV tuner and FM radio designs.

Availability

BB187 is available at Aetrix Electronics and suitable for VHF television tuners, FM radio front-ends, and voltage-controlled oscillators requiring stable component supply, tight capacitance matching, and ultra-compact SMD integration.

Supply support for BB187 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 BB187 belongs to NXP's RF discrete varactor family, engineered specifically for high-performance analog tuning in VHF broadcast and communication systems where linearity, matching, and miniaturization are critical.

FAQ

What is the maximum reverse voltage rating for the BB187?

The BB187 has an absolute maximum reverse voltage (VR) rating of 32 V DC and a peak reverse voltage (VRM) of 35 V when used with a 10 kΩ series resistor. Operating above these limits risks permanent junction damage per IEC 60134 limiting values. For reliable long-term operation in VHF tuners, NXP recommends staying below 24 V reverse bias - well within the BB187's specified safe operating area.

How does the BB187 achieve 2 % capacitance matching?

The BB187 achieves ≤2 % capacitance matching through a proprietary Direct Matching Assembly (DMA) process combined with gliding matching across sequences of 10 diodes. This method leverages tightly controlled planar diffusion and binning during wafer sort, not post-package trimming. The BB187's matching specification applies specifically to devices selected and shipped as matched pairs or groups - not to random units from standard reels.

Can the BB187 be used in UHF applications above 300 MHz?

The BB187 is characterized and optimized for VHF operation (30–300 MHz), with series resistance and Q-factor data validated up to 470 MHz. While functional in some UHF circuits, its Cd(2V)/Cd(25V) ratio ≥11 and low rs support best performance below 250 MHz. For dedicated UHF VCOs, NXP recommends alternatives like the BBY52,115 or SMV1232-011 - the BB187 remains ideal where VHF-specific linearity and matching are prioritized.

What does the marking code 'X' indicate on the BB187 package?

The marking code 'X' laser-etched on the BB187's SOD523 body identifies the device as the BB187 variant per NXP's ordering matrix. It is not a date or lot code. Combined with the cathode bar (Pin 1), this marking enables visual polarity verification during automated optical inspection and manual assembly - critical for correct reverse-bias orientation in tuning circuits where forward conduction must be avoided.

Is the BB187 suitable for automotive applications?

No - the BB187 is not automotive-qualified. NXP explicitly states in its datasheet that unless otherwise specified, its products (including BB187) are not tested or warranted for automotive use. It lacks AEC-Q200 qualification, extended temperature validation beyond Tj = –55 to +125 °C, and automotive-grade reliability screening. For automotive VHF tuning, designers must select AEC-Q200 qualified varactors with documented PPAP support.