NXP Semiconductors A3T18H408W24SR3

Overview

A3T18H408W24SR3 from NXP Semiconductors is a 56 W asymmetrical Doherty RF power LDMOS transistor with N-channel enhancement-mode lateral structure, operating at 30 Vdc, delivering 15.4 dB typical power gain and 50.9% drain efficiency at 1840 MHz under W-CDMA conditions, designed for cellular base station power amplifiers covering 1805–1880 MHz.

For engineers reviewing the A3T18H408W24SR3 datasheet, A3T18H408W24SR3 pinout, A3T18H408W24SR3 application, or A3T18H408W24SR3 equivalent, key selection criteria include Doherty architecture support, 75 MHz instantaneous bandwidth capability, ruggedness under 10 dB PAR AWGN stress, and internal input/output matching for simplified PA design in macrocell infrastructure.

Technical Context

This device implements a dual-path asymmetrical Doherty topology with separate carrier (Side A) and peaking (Side B) transistors integrated in a single NI-780S-4L2L air-cavity package. It supports digital predistortion via wideband linearity (–35.9 dBc ACPR at 1880 MHz) and exhibits 0.2 dB gain flatness across 75 MHz at 56 W avg. output.

Thermal performance is defined by 0.45 °C/W junction-to-case resistance at 56 W avg., enabling stable operation up to +150 °C case temperature. The gate threshold voltages differ between paths (V_GS(th) = 1.3–2.3 V for Side A; 0.7–1.7 V for Side B), enabling precise bias control for Class AB/Class C hybrid operation.

Key Specifications

Pinout & Package

Package: NI-780S-4L2L - hermetically sealed air-cavity ceramic/metal package with integrated thermal slug, optimized for RF power dissipation and broadband impedance stability.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF power amplifier applications.

Compared with MRF6VP2600HR5 and A3T18H408W24SR2, the A3T18H408W24SR3 delivers optimized Doherty linearity and thermal management for 56 W avg. LTE Band 3 deployments, with no layout change required when migrating from R2 to R3 due to identical footprint and solder reflow profile.

Availability

A3T18H408W24SR3 is available at Aetrix Electronics and suitable for macrocell base stations, massive MIMO active antenna units, and remote radio heads requiring stable component supply with full traceability and lifecycle support.

Supply support for A3T18H408W24SR3 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 leader specializing in secure connectivity solutions for automotive, industrial, and communications markets, with headquarters in Eindhoven, Netherlands.

The Airfast RF Power portfolio delivers high-efficiency LDMOS and GaN transistors engineered specifically for cellular infrastructure-enabling energy-efficient, spectrally clean, and thermally robust base station power amplifiers.

FAQ

What is the maximum safe operating drain voltage for A3T18H408W24SR3?

The A3T18H408W24SR3 has a maximum drain-source voltage rating of +65 Vdc. However, its recommended operating voltage is 30 Vdc for standard Doherty operation, with absolute maximum V_DD of 32 Vdc per Table 1. Exceeding 32 Vdc risks permanent damage even if within the ±65 Vdc V_DSS limit, as the device is characterized and qualified for 30 Vdc bias in production test fixtures.

Does A3T18H408W24SR3 require external input/output matching networks?

No, the A3T18H408W24SR3 is internally matched on both input and output per Table 5 footnote. Its NI-780S-4L2L package integrates broadband matching to 50 Ω, allowing direct connection to standard RF test equipment and PA board layouts without discrete matching components-verified in NXP's production test fixture with 50 Ω system impedance.

How does the A3T18H408W24SR3 support digital predistortion (DPD)?

The A3T18H408W24SR3 supports DPD through its wide instantaneous bandwidth (75 MHz), low AM/PM distortion (–15° max across band), and consistent –35.9 dBc ACPR at 1880 MHz. These traits enable accurate inverse modeling in real-time DPD algorithms, confirmed in NXP's functional tests using single-carrier W-CDMA signals with 9.9 dB PAR at 0.01% CCDF probability.

What is the thermal resistance value for A3T18H408W24SR3, and how is it measured?

The A3T18H408W24SR3 has a junction-to-case thermal resistance (R_θJC) of 0.45 °C/W, measured at 25°C case temperature under 56 W avg. W-CDMA conditions (30 Vdc, IDQA = 350 mA, VGSB = 0.3 Vdc, 1840 MHz) per AN1955 methodology. This value is validated using transient thermal measurement techniques on production units in NXP's RF power lab.

Can A3T18H408W24SR3 operate with independent VDD supplies on pins 3 and 6?

No-A3T18H408W24SR3 cannot operate with V_DD current supplied separately through pin 3 and pin 6. Per Figure 1 note and Table 5 footnote, V_DDA and V_DDB must be tied together and powered by a single DC supply. Attempting independent biasing violates the internal Doherty load modulation scheme and may cause instability or device failure.