NXP Semiconductors MC13851-2400EVK

Overview

MC13851-2400EVK from Freescale Semiconductor is an evaluation kit for the MC13851 2.4 GHz low-noise amplifier with integrated bypass switch, designed to demonstrate RF performance at 2400 MHz with 15.7 dB typical gain, 1.52 dB noise figure, and 17.5 dBm OIP3 in active mode. It supports rapid prototyping of WLAN, Bluetooth, and ISM-band front-end receivers requiring dynamic range optimization via logic-controlled gain/bypass/standby modes.

For engineers reviewing the MC13851-2400EVK datasheet, MC13851-2400EVK pinout, MC13851-2400EVK application, or MC13851-2400EVK equivalent, this board provides fully characterized 2400 MHz reference design with SMA connectors, bill-of-materials traceability, and measured S-parameter data - enabling validation of LNA integration, bias tuning, and return loss matching in compact RF layouts.

Technical Context

The MC13851-2400EVK implements a fixed-frequency 2400 MHz tuned circuit using Murata 0402 passive components (C1=2.4 pF, L1=3.6 nH, L2=2 nH, R3=620 Ω), optimized for conjugate-matched trade-offs between noise figure, IP3, and input/output return loss (>–9 dB). It uses the MC13851's MLPD-8 package with exposed thermal pad soldered to PCB ground.

Operation is controlled via two logic pins (Enable and Gain) supporting three states: High Gain (18.7 dB @ 1960 MHz), Bypass (–5.5 dB @ 2400 MHz), and Standby (<4 μA). Bias current is set by external R1 (1.2 kΩ or 1.5 kΩ), enabling adjustment between 3.8–5.8 mA active current while maintaining unconditional stability across 1000–2500 MHz.

Key Specifications

Availability

MC13851-2400EVK is available at Aetrix Electronics and suitable for WLAN infrastructure development, Bluetooth module validation, and ISM-band IoT sensor node design requiring stable component supply and repeatable RF characterization.

Supply support for MC13851-2400EVK 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

Freescale Semiconductor (now part of NXP Semiconductors) is a global leader in RF analog and mixed-signal ICs, specializing in high-performance wireless front-end solutions for cellular, GPS, and short-range communication systems.

The MC13851 product line delivers cost-effective, small-footprint LNAs with integrated bypass switches for frequency-agile receivers operating from 1000–2500 MHz, targeting power-constrained and space-limited RF applications.

FAQ

What is the primary function of the MC13851-2400EVK?

The MC13851-2400EVK is a dedicated evaluation board for the MC13851 low-noise amplifier, configured specifically for 2400 MHz operation. It provides a fully assembled, tested, and characterized reference design with SMA connectors, enabling engineers to validate RF performance metrics-including gain, noise figure, OIP3, and return loss-without developing custom PCBs. The MC13851-2400EVK directly demonstrates how the MC13851 integrates into real-world 2.4 GHz ISM-band systems.

Does the MC13851-2400EVK support multiple bias configurations?

Yes, the MC13851-2400EVK supports dual bias resistor options: R1 = 1.2 kΩ (4.8–5.8 mA active current) and R1 = 1.5 kΩ (3.8–4.8 mA active current), as documented in Table 9 of the MC13851 datasheet. This allows designers to trade off linearity (higher IP3 at 1.2 kΩ) versus current consumption (lower Icc at 1.5 kΩ) while maintaining stable 2400 MHz operation. The MC13851-2400EVK layout accommodates both values via footprint compatibility.

Can the MC13851-2400EVK be used for frequencies other than 2400 MHz?

No - the MC13851-2400EVK is a fixed-frequency evaluation board optimized exclusively for 2400 MHz. Its matching network (L1=3.6 nH, C1=2.4 pF, L2=2 nH, R3=620 Ω) is tuned for that band; using it at other frequencies (e.g., 1575 MHz or 2140 MHz) yields degraded gain, noise figure, and return loss. For other bands, Freescale provides separate EVKs: MC13851-1575EVK, MC13851-1960EVK, and MC13851-2140EVK.

How does the bypass mode operate on the MC13851-2400EVK?

On the MC13851-2400EVK, bypass mode is activated by setting the Gain pin low and Enable pin high (per Table 3 truth table), resulting in –5.5 dB insertion loss, 5.2–5.8 dB noise figure, and >24 dBm IIP3. This mode preserves high input intercept performance during strong signal events, improving dynamic range without altering external filtering - critical for systems with duplexers or bandpass filters. The MC13851-2400EVK maintains consistent return loss (S11/S22 > –14 dB) in both active and bypass states.

Is thermal management addressed on the MC13851-2400EVK?

Yes - the MC13851-2400EVK implements mandatory thermal design per MC13851 packaging requirements: the MLPD-8 package's exposed center thermal pad is soldered directly to a large copper pour on the PCB, ensuring junction-to-ambient thermal resistance remains near the specified 90 °C/W. This prevents thermal drift during extended RF testing and supports reliable operation at ambient temperatures up to +85 °C, as validated in Freescale's characterization data.