MRF5S4140HR3 - 465MHz 28V 28W RF Power LDMOS | NXP
MPN: MRF5S4140HR3 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $48.5 | $48.50 |
| 10 | $43.2 | $432.00 |
| 100 | $38.75 | $3,875.00 |
| 500 | $34.1 | $17,050.00 |
| 1,000 | $30.55 | $30,550.00 |
MRF5S4140HR3 Overview
An RF power LDMOS (Laterally Diffused Metal-Oxide Semiconductor) transistor is a specialized power MOSFET optimized for high-frequency, high-power amplification. It is a subset of the broader discrete power MOSFET family and is widely used as the final-stage or driver amplifier in wireless base stations, broadcast transmitters, and industrial RF generators. LDMOS devices combine the high breakdown voltage and thermal robustness of bipolar transistors with the switching simplicity of MOSFETs, and they dominate cellular and UHF base-station amplifier stages because of their high gain, high efficiency, and broadband RF characteristics.
The MRF5S4140HR3 key parameters include 28 W typical output power, 21 dB power gain, 28 V typical operating drain voltage, 65 V maximum drain-source rating, and operation across 400-500 MHz. The lateral structure provides excellent thermal stability and broadband input/output matching, while the NI-780H ceramic flange package offers low thermal resistance and straightforward bolt-down heatsinking for high-duty-cycle base-station operation. Internal electrostatic discharge (ESD) protection and stable gain across frequency simplify board-level design.
Architecturally, the MRF5S4140HR3 uses a laterally diffused MOS channel with a heavily doped drain region for high breakdown voltage and low on-resistance. The internal matching networks are pre-tuned for the 400-500 MHz band, and the device exhibits high power-added efficiency when operated in Class AB bias. Designers should observe the manufacturer-recommended bias sequence (gate-before-drain) and use gate-source pull-down resistors for safe shutdown.
Typical applications include 450 MHz CDMA, TDMA, and LTE private-network base-station amplifiers, UHF broadcast transmitters, industrial RF heating, and amateur radio amplifiers. The 28 W average power level is well matched to single-sector or repeater-station PA designs.
When designing with this part, provide a low-inductance ground path through the flange mounting surface and adequate copper heat-spreading beneath the PCB. Operate within the device's safe operating area envelope and follow the manufacturer bias and sequencing guidelines to prevent in-rush currents that could damage the gate oxide.
This page synthesizes distributor availability, drop-in alternatives in the same NI-780 family, and practical design notes that are not consolidated on the manufacturer datasheet alone.
Drop-in alternatives for MRF5S4140HR3 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MRF5S4140HR3 (same form factor and footprint) — differing in Application, Power Gain, Test Frequency, Transistor Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MRF5S4140HSR3
✅ Drop-In📋 Reference alternative (not in catalog)
MRF5S19060HR3
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MRF5S9101NR1
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$61.4 / Unit
View Datasheet →MRF5S4140HR3 Maximum Ratings & Electrical Characteristics
| Transistor Type | N-Channel Enhancement-Mode Lateral MOSFET (LDMOS) |
| Frequency Band | 400-500 MHz |
| Test Frequency | 465 MHz |
| Typical Output Power | 28 W avg. |
| Power Gain | 21 dB at 465 MHz |
| Operating Drain Voltage | 28 V typical |
| Drain-Source Voltage (Max) | 65 V |
| DC Bias Current (Id) | 1.25 A typical |
| Configuration | Single, common-source |
| Maximum Power Dissipation | 427 W absolute (per partstack profile) |
| Package | NI-780H-2L (ceramic flange mount) |
| Mounting Style | Flange mount, surface-mount leads |
| Input Matching | Internal, broadband |
| Operating Mode | Class AB, large-signal |
| Application | Single N-CDMA base station PA, 450 MHz band |
MRF5S4140HR3 Pin Configuration
| Pin 1 | Gate — RF input / gate bias |
| Pin 2 | Drain — RF output / drain supply (28 V typical) |
| Pin 3 | Flange — Source / thermal ground (bolt-down) |
DC Safe Operating Area
Typical Applications
MRF5S4140HR3 is suitable for 6 applications: 450 MHz CDMA Base-Station Final PA, UHF Broadcast Transmitter PA, Industrial RF Heating & Drying, Public-Safety & Private Mobile Radio Repeater, Amateur Radio UHF Power Amplifier, Driver Stage for Higher-Power UHF PAs.
450 MHz CDMA Base-Station Final PA
The MRF5S4140HR3 is purpose-built as the final-stage PA in 465 MHz single-N-CDMA base-station equipment. Its 28 W average output power, 21 dB gain, and 65 V Vds rating provide linearity-compliant power for single-sector or repeater station transmitters. The NI-780H-2L ceramic flange-mount package enables direct thermal coupling to chassis heatsinks, while internal broadband matching eliminates external input-matching components, simplifying PCB layout and reducing BOM cost in volume base-station production runs.
Recommended
UHF Broadcast Transmitter PA
For UHF broadcast transmitter service adjacent to the 400-500 MHz band, the MRF5S4140HR3's high drain breakdown voltage (65 V), 28 W continuous rating, and broadband matching make it suitable as a driver or low-power final stage. Designers can combine multiple devices in paralleled push-pull configurations to scale output power while retaining the per-device efficiency advantages of LDMOS technology. The 21 dB gain reduces the required driver-stage count, simplifying the broadcast RF chain.
Recommended
Industrial RF Heating & Drying
Industrial RF heating systems operating in the 400-500 MHz ISM-adjacent band benefit from the MRF5S4140HR3's 28 W power level and robust flange-mount thermal path. The lateral MOSFET structure tolerates high VSWR conditions typical of variable-load industrial processes, and the 65 V Vds rating gives significant transient headroom for mismatch events. The part's broadband matching simplifies tuner design across varying applicator impedances.
Recommended
Public-Safety & Private Mobile Radio Repeater
Public-safety and 450 MHz private LMR repeater stations benefit from the MRF5S4140HR3's linearity, 28 W typical output, and base-station-grade reliability. The 21 dB gain supports compact single-PA designs where board space is constrained, while the NI-780H-2L flange package simplifies integration into weatherized repeater enclosures. The broadband 400-500 MHz coverage accommodates multiple narrowband modulation schemes (FM, DMR, P25) without re-matching.
Recommended
Amateur Radio UHF Power Amplifier
Amateur radio constructors building 70 cm and 450 MHz amplifier projects use the MRF5S4140HR3 as a proven, documented final PA. The 28 W rating suits intermediate-power station builds, and the standard NI-780H package is supported by published reference designs from the manufacturer. Gate bias sequencing recommendations from the NXP datasheet enable safe first-time integration by experienced amateur RF designers.
Recommended
Driver Stage for Higher-Power UHF PAs
When designing higher-power UHF power amplifiers (100 W and above), the MRF5S4140HR3's 21 dB gain and 28 W output can drive subsequent LDMOS or bipolar final stages with margin. Used as a driver, the device's broadband matching reduces inter-stage network complexity and improves overall composite efficiency. The 65 V Vds rating also accommodates intermediate driver rails in compound amplifier architectures.
Recommended
Recommended Products Summary
Engineering reference data for MRF5S4140HR3 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MRF5S4140HSR3 | MRF5S19060HR3 | MRF5S9101NR1 |
|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | NI-780H-2L | NI-780H-2L - same | NI-780H-2L - same | NI-780-2L - same family |
| Frequency Band | 400-500 MHz | 400-500 MHz - same | 1900-2000 MHz (1.9 GHz) | 900-1000 MHz |
| Output Power (Avg) | 28 W | 28 W - same | 60 W | ~100 W (P1dB) |
| Power Gain | 21 dB | 21 dB - same | 20 dB | ~16-18 dB |
| Drain Voltage (Vdd) | 28 V | 28 V - same | 28 V | 26 V |
| Maximum Vds | 65 V | 65 V - same | 65 V | 65 V |
| Lead Forming | Straight leads (R3 suffix) | Formed/offset leads (SR3 suffix) | Straight leads (R3) | Notch/formed (NR1) |
Key Differentiators
- Purpose-built 465 MHz single N-CDMA optimization (vs MRF5S9101NR1)
- Higher gain than larger 1.9 GHz device (vs MRF5S19060HR3)
- Same-die pin-form flexibility (vs MRF5S4140HSR3)
Design Notes
The NI-780H-2L ceramic flange package is designed for direct bolt-down mounting to an external heatsink using thermal interface material (TIM) such as thermal grease or graphite pad. Estimated: at 28 W output and ~50% efficiency, dissipation inside the part is ~28 W; junction-to-case thermal resistance must be confirmed from the datasheet thermal curve. Apply 0.05-0.1 N-m torque on mounting screws to avoid ceramic cracking while ensuring low thermal impedance. A thermal pad with at least 4 C/W below the flange is recommended for continuous CDMA operation.
Always apply gate bias BEFORE drain voltage when powering up the MRF5S4140HR3; applying 28 V to the drain with the gate at zero volts can cause uncontrolled current draw and possible device damage. Include a 10 kohm gate-to-source pull-down resistor to ensure the device stays off during fault conditions. Sequence the negative gate voltage (or positive Vgs_off) before removing drain supply during shutdown.
Provide a low-inductance ground return by mounting the flange directly to a clean, copper-plated chassis surface with multiple short ground vias around the PCB mounting area. Place input matching components as close as possible to the gate pin to minimize parasitic inductance, and use a 50 ohm microstrip transmission line from the input connector to the gate matching network. The drain bias feed should include a quarter-wave stub or RF choke to prevent leakage of RF into the DC supply.
Use a regulated 28 V DC supply capable of delivering at least 3 A continuous and 5 A peak for pulse operation. Add bulk decoupling (>= 100 uF electrolytic + 1 uF ceramic) directly at the drain bias feed to handle peak current demands of CDMA modulation. Include reverse-polarity protection and an inrush limiter on the drain rail to prevent hot-plug damage to the LDMOS drain structure.
Compliance Information
Compliance status not explicitly listed in the verified web data provided (as of 2026-10-16). Designers should request the latest material declaration from NXP for production qualification. NI-780 ceramic flange packages typically offer lead-free / RoHS variants identified by part-number suffix.
