NXP Semiconductors AFT21S230SR3

Overview

AFT21S230SR3 from NXP Semiconductors (formerly Freescale) is a 50 W average RF power LDMOS transistor designed for cellular base station amplifiers operating in the 2110–2170 MHz band. It delivers 17.2 dB power gain, 31.8% drain efficiency, and –34.8 dBc ACPR at 2170 MHz under single-carrier W-CDMA conditions (V_DD = 28 V, I_DQ = 1500 mA, P_out = 50 W avg.). Its NI-780S-2L4S package supports Doherty amplifier architectures with dual VBW leads.

For engineers reviewing the AFT21S230SR3 datasheet, AFT21S230SR3 pinout, AFT21S230SR3 application, or AFT21S230SR3 equivalent, key selection criteria include its 2110–2170 MHz bandwidth, 50 W average RF output capability, gate threshold voltage of 1.5–2.5 V, optimized load-pull impedance for P1dB efficiency, and ESD robustness per JESD22-A114 Class 2.

Technical Context

This N-channel enhancement-mode lateral MOSFET operates with fixed 28 V DC supply and 1500 mA quiescent drain current. Its internally matched input and output enable direct integration into 50 Ω systems without external matching networks across the full 60 MHz bandwidth. The device features dual VBW (voltage bias) terminals to support flexible DC feed configurations-pins 4 & 6 for AFT21S230S variants-enabling reduced layout complexity in high-efficiency Doherty PA stages.

Thermal design is enabled by low junction-to-case thermal resistance (0.43 °C/W at 80 °C case temperature), validated under 50 W CW operation. Its gate structure supports extended negative V_GS range for stable Class C operation and digital predistortion (DPD) linearization, with AM/PM distortion measured at –19.3° maximum across the band.

Key Specifications

Pinout & Package

Package: NI-780S-2L4S - ceramic/metal flange-mount package with 44 mm tape width, 13-inch reel (250 units/reel), optimized for high-power RF thermal management and PCB-level Doherty integration.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MRF6VP2600HR5 and AFM36H035N, the AFT21S230SR3 offers optimal balance of 50 W average output, 2110–2170 MHz band focus, and NI-780S-2L4S thermal-mechanical compatibility-making it the preferred choice for Band I uplink RRHs and microcell Doherty PAs where layout space and 28 V infrastructure are fixed constraints.

Availability

AFT21S230SR3 is available at Aetrix Electronics and suitable for macro base station transmitters, Doherty power amplifiers, W-CDMA base station PAs, and DPD-enabled remote radio heads requiring stable component supply and long-term lifecycle support.

Supply support for AFT21S230SR3 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 deep heritage in RF power from its Freescale acquisition.

The AFT21S230SR3 belongs to the AIRFAST® RF Power LDMOS family, engineered specifically for energy-efficient, digitally linearized cellular infrastructure amplifiers operating in licensed sub-3 GHz bands.

FAQ

What is the maximum continuous wave (CW) output power rating for AFT21S230SR3?

The AFT21S230SR3 supports 161 W CW output when DC current is supplied through the drain lead (pin 5), derating at 0.75 W/°C above 25 °C case temperature. When biased via pins 4 and 6, the rating drops to 104 W CW with 0.44 W/°C derating. These values are validated per Freescale's Maximum Ratings table and apply only under specified thermal conditions (TC ≤ 80 °C). The AFT21S230SR3 must be mounted on a heatsink capable of maintaining TC within limits to sustain rated CW power.

Does AFT21S230SR3 require external input/output matching networks?

No, the AFT21S230SR3 is internally matched on both input and output for 50 Ω systems across 2110–2170 MHz, as confirmed in Table 4 and Figure 4 test circuit documentation. This eliminates discrete matching components in standard PA layouts. However, external harmonic filtering and stabilization networks may still be required depending on system-level spectral and stability requirements-especially in broadband or multi-band configurations outside the specified band.

What is the gate threshold voltage range for AFT21S230SR3, and how does it impact bias design?

The AFT21S230SR3 has a gate threshold voltage (V_GS(th)) range of 1.5–2.5 Vdc at V_DS = 10 V and I_D = 291 µA, per Table 4. This tight tolerance enables predictable Class AB biasing without binning. For stable 1500 mA quiescent current, the gate quiescent voltage (V_GS(Q)) is specified as 2.2–3.2 Vdc-guiding the design of precision gate bias circuits using low-drift references and feedback regulation to maintain linearity over temperature and unit variance.

How does the dual VBW pin configuration (pins 4 and 6) affect PCB layout for AFT21S230SR3?

The dual VBW pins on the AFT21S230SR3 provide two independent paths for DC bias injection to the drain, enabling flexible PCB routing in Doherty or multi-stage amplifier layouts. Using both pins reduces current density per trace and minimizes parasitic inductance compared to single-point feeding. Layout best practices require symmetric copper pours, Kelvin sensing traces for bias monitoring, and separation from RF signal paths to avoid coupling-details validated in Freescale's Figure 4 test circuit and AN1955 thermal guidelines.

Is AFT21S230SR3 compatible with digital predistortion (DPD) systems, and what parameters support this?

Yes, the AFT21S230SR3 is explicitly designed for DPD systems, as stated in its Features section. Key supporting parameters include low AM/PM distortion (–19.3° max), high linearity (–35.7 dBc ACPR at 2110 MHz), and stable gain vs. temperature (0.016 dB/°C). Its extended negative V_GS range (–6.0 V) improves Class C peaking device control in Doherty-DPD hybrids. These characteristics are measured under W-CDMA signal conditions with 9.9 dB PAR, confirming suitability for real-world DPD deployment in 3GPP-compliant base stations.