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MRF338
MRF338
| Part Number | MRF338 |
|---|---|
| Manufacturer | NXP Semiconductors / Motorola |
| Category | Discrete Semiconductor Products > Transistors > Bipolar (BJT) > RF Power Transistors |
| Description | NPN Silicon Epitaxial Planar RF Power Transistor, Optimized for 400MHz~512MHz UHF Band, Typical 80W Output Power @ 28V Supply, Hermetic Ceramic Flange Package. |
| Stock Status | In Stock |
| Origin | Original |
Product Overview
MRF338 is an NPN epitaxial planar RF power transistor developed by Motorola (NXP). Designed for CW and pulsed UHF power amplifiers covering 400~512MHz, it provides typical 80W output power at 28V. Original Motorola and ASI compatible two versions are supplied. Equipped with emitter ballasting, it withstands load mismatch. Hermetic ceramic flange package ensures stable performance for military radio, avionics and industrial RF systems.
Core Advantages
Optimized for 400~512MHz UHF Communication Band
Tuned for military and commercial UHF radio applications, ideal for final-stage power amplifiers using standard 28V supply.
Two Version Options In Stock
Original Motorola edition and improved ASI compatible variant available, satisfying different peak current design demands.
Built-in Emitter Ballast Structure
Effectively prevents thermal runaway and improves durability under high VSWR mismatched load conditions.
Hermetic Ceramic Flange Packaging
Flange mounting enables efficient heat dissipation; sealed package withstands humid, outdoor and airborne harsh environments.
Key Specifications
| Brand | NXP Semiconductors / Motorola |
|---|---|
| RoHS Status | RoHS Compliant Option Available |
| EDA/CAD | Symbol, Footprint & 3D Model Available |
| Warranty | 1-Year Standard Quality Warranty |
| Package / Case | Case 211-07 (Style 1 / Flange Mount Hermetic Ceramic) |
| Mounting Type | Chassis Mount / Flange Bolt-Down Mounting |
| Surface Marking / Silkscreen | MRF338 Marking |
| Transistor Type | NPN Silicon Epitaxial Planar RF Power Transistor |
| Frequency Range | 400 MHz to 512 MHz (UHF Band) |
| Output Power | 80 W (Typ. at VCC = 28V, f = 470MHz) |
| Supply Voltage | 28 V DC Nominal (VCBO = 60V, VCEO = 30V, VEBO=4V) |
| Power Gain | Typ. 7.3 dB ~ 8.8 dB @ 400–512MHz |
| Collector Efficiency | Typ. 50% ~ 60% |
| DC Current Gain (hFE) | 20 ~ 80 (IC=4A, VCE=5V) |
| Output Capacitance (Cob) | 95 ~ 125 pF (Vcb=28V, f=1MHz) |
| Total Power Dissipation (Pd) | 250W @ Tc=25°C |
| Max Collector Current (Ic) | 9A (Motorola Original) / 12A (ASI Version) |
| Thermal Resistance θJC | 0.7°C/W (ASI Data) |
| Operating Junction Temperature | -65°C ~ +150°C |
| Packaging Format | Tray / Anti-Static Protective Box |
Typical Applications
- Military tactical UHF communication transmitters (400~512MHz)
- Avionics airborne UHF communication power amplifiers
- UHF land mobile radio base station RF power stages
- Industrial scientific RF signal generator & plasma excitation equipment
- Broadband RF power combiner and high-power amplifier modules
Order & Shipping Info
| Minimum Order Quantity (MOQ) | 1 Piece |
|---|---|
| Processing Time | Ship within 1-2 business days |
| Global Transit Time | 3-7 working days |
| Available Shipping | DHL, UPS, FedEx, EMS |
| Payment Methods | T/T Bank Transfer, PayPal, Credit Card, Western Union |
Technical Support
Please submit inquiry for complete datasheet, sample application, bulk quotation and stock confirmation. We will reply within 24 working hours.
Frequently Asked Questions
Q1: What frequency band is MRF338 designed for?
A: MRF338 is optimized for 400 MHz ~ 512 MHz UHF band. It cannot reach rated power for 225–400MHz applications, which normally adopt MRF337.
Q2: What is the difference between original Motorola MRF338 and ASI compatible MRF338?
A: Pinout and package are fully compatible. Original Motorola version max collector current Ic=9A; ASI improved version reaches 12A, with integrated input matching network for simpler amplifier design. Circuit re-verification is required if switching between the two versions.
Q3: What alternative parts can replace MRF338?
A: Similar alternatives: MRF339 (higher output power), MRF337 (lower frequency band). Cross-brand option: MACOM UHF flange RF transistors. Any replacement needs circuit matching retuning before mass use.
Q4: What is the difference between MRF337 and MRF338?
A: MRF337: 225–400MHz UHF; MRF338: 400–512MHz. Do not mix the two models during procurement, their frequency characteristics cannot be interchanged directly.
Q5: Can MRF338 run continuously at maximum junction temperature 150°C?
A: 150°C is absolute maximum limit. For long service life, keep steady junction temperature below 130°C with proper heatsink and thermal grease.
Q6: Is a heatsink required for MRF338 operation?
A: Yes. This high-power RF transistor must be firmly mounted on copper heatsink with thermal interface material. Insufficient cooling will quickly cause thermal damage under continuous operation.
Q7: Can MRF338 work under pulsed operation?
A: Yes. It supports both continuous wave (CW) and pulsed modes. Higher peak power can be achieved under short pulse and low duty cycle.
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