NXP Semiconductors BAP55LX,315

Overview

BAP55LX from NXP Semiconductors is a silicon PIN diode in a DFN1006D-2 (SOD882D) leadless ultra-small SMD package, designed for high-speed RF switching and attenuation up to 3 GHz. It delivers 0.18 pF typical diode capacitance at 20 V reverse bias, 0.8 Ω typical forward resistance at 100 mA, and 12 dB isolation at 2450 MHz - enabling compact, high-isolation RF front-end designs in mobile and wireless infrastructure.

For engineers reviewing the BAP55LX datasheet, BAP55LX pinout, BAP55LX application, or BAP55LX equivalent, key selection criteria include its AEC-Q101 qualification, sub-0.5 nH series inductance, 0.27 μs charge carrier lifetime, and compatibility with 50 Ω stripline circuits in series or parallel configurations.

Technical Context

The BAP55LX operates as a voltage-controlled RF resistor: its intrinsic region enables low capacitance and fast carrier sweep-out under forward bias, while reverse bias yields high impedance and strong isolation. Its performance is defined by controlled carrier lifetime (0.27 μs typ), minimal parasitic inductance (0.4 nH), and stable C_V/R_F trade-off across 900–2450 MHz bands.

It supports both series and parallel RF switch topologies, with S-parameter data validated from 100 MHz to 10 GHz under seven forward current levels (0.1–100 mA). The cathode-marked DFN1006D-2 package ensures repeatable placement and thermal resistance of 78 K/W to solder point.

Key Specifications

Pinout & Package

DFN1006D-2 package: ultra-small leadless plastic SMD with 2 terminals, body dimensions 1.0 × 0.6 × 0.4 mm, cathode indicated by marking bar on top surface.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF PIN diode switching applications.

Compared with BAR50-02V and MBD770F, the BAP55LX offers superior high-frequency isolation and automotive-grade reliability in the smallest footprint - making it optimal for space-constrained, multi-band RF switches demanding consistent 2.45 GHz performance and AEC-Q101 compliance.

Availability

BAP55LX is available at Aetrix Electronics and suitable for cellular antenna switching, Wi-Fi front-end attenuation, and automotive keyless entry systems requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for BAP55LX 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 IoT applications.

The BAP55LX belongs to NXP's high-frequency discrete portfolio, engineered specifically for RF signal routing and attenuation in compact wireless devices - emphasizing low parasitics, AEC-Q101 reliability, and seamless integration into 50 Ω PCB layouts.

FAQ

What is the maximum RF frequency range supported by the BAP55LX?

The BAP55LX is characterized for operation up to 3 GHz, with verified isolation and insertion loss performance at 900 MHz, 1800 MHz, and 2450 MHz. S-parameter data extends to 10 GHz, confirming usability in higher-frequency ISM and UWB applications when operated within its rated forward current and voltage limits. The BAP55LX maintains stable RF behavior due to its ultra-low series inductance and controlled carrier lifetime.

Does the BAP55LX require external bias circuitry for RF switching?

Yes, the BAP55LX requires DC bias control to switch between low-resistance (forward-biased anode) and high-impedance (reverse-biased) states. A series resistor and DC blocking capacitor are typically used to inject bias current while preserving RF path integrity. The BAP55LX supports bias currents from 0.1 mA to 100 mA, with forward resistance scaling predictably across this range - enabling precise analog attenuation control without additional active components.

Is the BAP55LX pin-compatible with other DFN1006D-2 diodes?

The BAP55LX uses standard DFN1006D-2 pinout (cathode at Pin 1, anode at Pin 2), matching mechanical and solder-pad layout with other SOD882D-packaged diodes like the BAR50-02V. However, electrical characteristics - including capacitance, forward resistance, and carrier lifetime - differ significantly. PCB layout reuse is possible, but circuit performance validation is required when substituting the BAP55LX for other diodes in the same package.

How does the AEC-Q101 qualification impact BAP55LX use in non-automotive designs?

AEC-Q101 qualification certifies the BAP55LX for extended temperature operation (–65 °C to +150 °C junction), robustness against thermal cycling, and reliability under high-humidity conditions - benefits that directly improve field failure rates in industrial, medical, and outdoor wireless equipment. While not mandatory outside automotive, this qualification provides measurable margin for mission-critical RF paths where long-term parametric stability is essential. The BAP55LX leverages this qualification without added cost or size penalty.

Can the BAP55LX be used in parallel RF switch configurations?

Yes, the BAP55LX is explicitly characterized for parallel configuration, with S-parameter data (Figures 10–12) showing S11, S22, and S21 performance across 0.1–100 mA bias currents up to 10 GHz. In parallel mode, it functions as a shunt switch: forward bias shorts the RF path to ground, providing attenuation, while reverse bias presents high impedance. Its low series inductance and symmetric package ensure balanced performance in both series and parallel topologies - a key advantage confirmed in the BAP55LX datasheet.