NXP Semiconductors MRF7S21170HR5

Overview

MRF7S21170HR5 from NXP Semiconductors (formerly Freescale) is a 2110–2170 MHz, 50 W average power, N-channel enhancement-mode lateral MOSFET RF power transistor optimized for CDMA and multicarrier W-CDMA base station amplifiers. It delivers 16 dB power gain, 31% drain efficiency, and –37 dBc ACPR at 5 MHz offset under 28 V, 1400 mA bias with 50 W avg. output in single-carrier W-CDMA. Designed for Class AB/C operation in PCN-PCS/cellular and WLL infrastructure.

For engineers reviewing the MRF7S21170HR5 datasheet, MRF7S21170HR5 pinout, MRF7S21170HR5 application, or MRF7S21170HR5 equivalent, this page provides verified RF power transistor specifications, thermal and impedance data, Doherty-optimized performance metrics, and real-world W-CDMA linearity validation including PAR, ACPR, and IMD behavior - all critical for macrocell PA design and digital predistortion implementation.

Technical Context

This LDMOS device operates in the 2110–2170 MHz band with internally matched input/output impedances (e.g., Z_source = 4.40 – j9.42 Ω, Z_load = 0.92 – j2.76 Ω at 2140 MHz), enabling simplified broadband matching network design. Its gate threshold voltage (1.2–2.7 V) and quiescent gate voltage (2.7 V typ.) support stable Class AB biasing, while the extended negative V_GS range (–6.0 V) enables robust Class C operation.

The transistor is characterized for pulsed CW and continuous-wave conditions, supporting 170 W PEP output and 5:1 VSWR tolerance at 32 Vdc. Its series-equivalent large-signal impedance parameters, 100% PAR-tested output capability, and integrated ESD protection (HBM Class 1A) are validated per JESD22-A114 and documented in Freescale's AN1955 thermal methodology and EB212 impedance application notes.

Key Specifications

Pinout & Package

Package: NI-880S (Case 465C-03), flanged ceramic/metal hermetic package with source-connected tab for direct heatsink mounting. Thermal resistance R_θJC = 0.31°C/W at 170 W CW, case temperature 80°C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MRF7S21170HSR5 and AFM905S, the MRF7S21170HR5 offers superior thermal resistance and highest guaranteed PEP (170 W), making it optimal for high-reliability macrocell sites demanding maximum output headroom and long-term MTTF under sustained 50 W avg. operation.

Availability

MRF7S21170HR5 is available at Aetrix Electronics and suitable for macrocell base station PA, W-CDMA multicarrier amplifiers, and Doherty power amplifier designs requiring stable component supply, high linearity, and proven 2100 MHz band reliability.

Supply support for MRF7S21170HR5 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 leader in high-performance RF power solutions, formed from the spin-off of Freescale Semiconductor's RF division. It specializes in LDMOS and GaN transistors for cellular infrastructure.

The MRF7S21170HR5 belongs to NXP's MRF7S family of high-efficiency, thermally robust LDMOS transistors designed specifically for 3G/4G macrocell and small-cell base station power amplifiers operating in licensed sub-3 GHz bands.

FAQ

What is the maximum continuous drain current rating for the MRF7S21170HR5?

The MRF7S21170HR5 does not specify a maximum continuous drain current (I_D) rating in its datasheet. Instead, it defines safe operating limits via junction temperature (T_J ≤ 225°C), case temperature (T_C ≤ 150°C), and thermal resistance (R_θJC = 0.31°C/W). Under typical 28 V, 1400 mA quiescent bias, the device delivers 50 W avg. output in W-CDMA. The MRF7S21170HR5 is characterized for pulsed and CW operation up to 170 W PEP, with current scaling determined by thermal management and V_DD compliance.

Does the MRF7S21170HR5 require external gate protection diodes?

No, the MRF7S21170HR5 includes integrated ESD protection rated to HBM Class 1A (±2 kV), Machine Model Class B, and CDM Class IV per JESD22 standards. This eliminates the need for external gate protection diodes in standard PCB layouts. However, proper RF grounding, controlled ESD handling during assembly, and adherence to Freescale's AN1955 thermal guidelines remain essential. The MRF7S21170HR5's gate oxide is hardened for production environments, but gate voltage must still stay within –6.0 V to +10 Vdc limits.

Can the MRF7S21170HR5 be used in Class C mode for narrowband applications?

Yes, the MRF7S21170HR5 is explicitly designed for Class C operation in narrowband PCS/cellular and WLL applications, supported by its extended negative gate-source voltage range (–6.0 V) and optimized transconductance profile. Its gate threshold voltage (1.2–2.7 V) and quiescent gate voltage (2.7 V typ.) allow precise bias point adjustment below pinch-off. The MRF7S21170HR5 achieves higher efficiency in Class C than standard LDMOS devices, especially when paired with harmonic tuning networks - as validated in Freescale's application notes for PCN-PCS radio systems.

What is the recommended gate bias network for the MRF7S21170HR5 in W-CDMA applications?

The recommended gate bias network for the MRF7S21170HR5 in W-CDMA applications uses a resistive divider to set V_GS(Q) = 2.7 V (typ.) at IDQ = 1400 mA, with fixture gate voltage V_GG(Q) = 4.5–6.5 V due to internal resistive divider effects. A stable, low-noise +5 V supply feeding a 10 kΩ/10 Ω resistor pair (per Freescale Test Circuit schematic) is standard. Decoupling with 10 µF and 0.1 pF capacitors near the gate pin suppresses RF feedback and supply noise. The MRF7S21170HR5's gate input impedance is highly capacitive; thus, the network must avoid resonance in-band and maintain stability across temperature.

How does the MRF7S21170HR5 perform under digital predistortion (DPD)?

The MRF7S21170HR5 demonstrates strong DPD compatibility, with Figure 10 showing >10 dB ACPR improvement (from –37 dBc to <–47 dBc) when memoryless and memory-based DPD are applied at 50 W avg. output. Its linearized AM/AM and AM/PM characteristics, low group delay variation (1.7 ns avg.), and tight part-to-part phase consistency (±18° six-sigma) enable rapid convergence of adaptive DPD algorithms. The MRF7S21170HR5's internally matched architecture minimizes baseband-to-RF latency, making it suitable for wideband DPD implementations up to 20 MHz signal bandwidth.