MRF5015

MRF5015 MOTOROLA | Alldatasheet

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MRF5015MOTOROLA RF DEVICE DATA The RF MOSFET Line /C0082/C0070 /C0080/C0111/C0119/C0101/C0114 /C0070/C0105/C0101/C0108/C0100 /C0069/C0102/C0102/C0101/C0099/C0116 /C0084/C0114/C0097/C0110/C0115/C0105/C0115/C0116/C0111/C0114 N–Channel Enhancement–Mode Designed for broadband commercial and industrial applications at frequen- cies to 520 MHz. The high gain and broadband performance of this device makes it ideal for large–signal, common source amplifier applications in 12.5 volt mobile, and base station FM equipment.

• Guaranteed Performance at 512 MHz, 12.5 Volts Output Power — 15 Watts Power Gain — 10 dB Min Efficiency — 50% Min
• Characterized with Series Equivalent Large–Signal Impedance Parameters
• S–Parameter Characterization at High Bias Levels
• Excellent Thermal Stability
• All Gold Metal for Ultra Reliability
• Capable of Handling 20:1 VSWR, @ 15.5 Vdc, 512 MHz, 2 dB Overdrive
• Circuit board photomaster available upon request by contacting RF Tactical Marketing in Phoenix, AZ. MAXIMUM RATINGS Rating Symbol Value Unit Drain–Source Voltage VDSS 36 Vdc Drain–Gate Voltage (RGS = 1 MΩ ) VDGR 36 Vdc Gate–Source Voltage VGS ± 20 Vdc Drain Current — Continuous ID 6 Adc Total Device Dissipation @ TC = 25°C Derate above 25°C PD 50 0.29 Watts W/°C Storage Temperature Range Tstg – 65 to +150 °C Operating Junction Temperature TJ 200 °C THERMAL CHARACTERISTICS Characteristic Symbol Max Unit Thermal Resistance, Junction to Case R θJC 3.5 °C/W ELECTRICAL CHARACTERISTICS (TC = 25°C unless otherwise noted.) Characteristic Symbol Min Typ Max Unit OFF CHARACTERISTICS Drain–Source Breakdown Voltage (VGS = 0, ID = 5 mAdc) V(BR)DSS 36 — — Vdc Zero Gate Voltage Drain Current (VDS = 15 Vdc, VGS = 0) IDSS — — 5 mAdc Gate–Source Leakage Current (VGS = 20 Vdc, VDS = 0) IGSS — — 2 µAdc (continued) NOTE – CAUTION – MOS devices are susceptible to damage from electrostatic charge. Reasonable precautions in handling and packaging MOS devices should be observed. Order this document by MRF5015/D /C0077/C0079/C0084/C0079/C0082/C0079/C0076/C0065 SEMICONDUCTOR TECHNICAL DATA /C0077/C0082/C0070/C0053/C0048/C0049/C0053 15 W, 512 MHz, 12.5 VOLTS N–CHANNEL BROADBAND RF POWER FET CASE 319–07, STYLE 3  Motorola, Inc. 1994 REV 6

Figure 1. 512 MHz Narrowband Test Circuit Electrical Schematic

520 MHz

470 MHzf = 400 MHz

Figure 2. Output Power versus Input Power Figure 3. Output Power versus Supply Voltage Figure 4. Output Power versus Gate Voltage Figure 5. Drain Current versus Gate Voltage Figure 6. Capacitance versus Voltage Figure 7. Gate–Source Voltage

Table 1. Common Source Scattering Parameters (VDS = 12.5 V)

The MRF5015 is a common–source, RF power, N–Chan- nel enhancement mode, Metal–Oxide Semiconductor Field– Effect Transistor (MOSFET). Motorola RF MOSFETs feature a vertical structure with a planar design. Motorola Application Note AN211A, “FETs in Theory and Practice,” is suggested reading for those not familiar with the construction and char- acteristics of FETs. This device was designed primarily for 12.5 volt VHF and UHF power amplifier applications. The major advantages of RF power MOSFETs include high gain, simple bias systems, relative immunity from thermal runaway, and the ability to withstand severely mismatched loads without suffering dam- age. MOSFET CAPACITANCES The physical structure of a MOSFET results in capacitors between all three terminals. The metal oxide gate structure determines the capacitors from gate–to–drain (Cgd), and gate–to–source (Cgs). The PN junction formed during fab- rication of the RF MOSFET results in a junction capacitance from drain–to–source (Cds). These capacitances are charac- terized as input (Ciss), output (Coss) and reverse transfer (Crss) capacitances on data sheets. The relationships be- tween the inter–terminal capacitances and those given on data sheets are shown below. The Ciss can be specified in two ways: 1. Drain shorted to source and positive voltage at the gate. 2. Positive voltage of the drain in respect to source and 2. zero volts at the gate. In the latter case, the numbers are lower. However, neither method represents the actual operating conditions in RF ap- plications. Drain C ds Source Gate C gd C gs C iss = Cgd + Cgs C oss = Cgd + Cds C rss = Cgd DRAIN CHARACTERISTICS One critical figure of merit for a FET is its static resistance in the full–on condition. This on–resistance, Rds(on), occurs in the linear region of the output characteristic and is speci- fied at a specific gate–source voltage and drain current. The drain–source voltage under these conditions is termed V ds(on). For MOSFETs, Vds(on) has a positive temperature coefficient at high temperatures because it contributes to the power dissipation within the device. GATE CHARACTERISTICS The gate of the RF MOSFET is a polysilicon material, and is electrically isolated from the source by a layer of oxide. The input resistance is very high, on the order of 109 Ω , re- sulting in a leakage current of a few nanoamperes. Gate control is achieved by applying a positive voltage to the gate greater than the gate–to–source threshold voltage, V GS(th). Gate Voltage Rating – Never exceed the gate voltage rat- ing. Exceeding the rated VGS can result in permanent dam- age to the oxide layer in the gate region. Gate Termination – The gates of these devices are es- sentially capacitors. Circuits that leave the gate open–cir- cuited or floating must be avoided. These conditions can result in turn–on of the devices due to voltage build–up on the input capacitor due to leakage currents or pickup. Gate Protection – These devices do not have an internal monolithic zener diode from gate–to–source. If gate protec- tion is required, an external zener diode is recommended with appropriate RF decoupling networks. Using a resistor to keep the gate–to–source impedance low also helps dampen transients and serves another impor- tant function. Voltage transients on the drain can be coupled to the gate through the parasitic gate–drain capacitance. If the gate–to–source impedance and the rate of voltage change on the drain are both high, then the signal coupled to the gate may be large enough to exceed the gate–threshold voltage and turn the device on. DC BIAS Since the MRF5015 is an enhancement mode FET, drain current flows only when the gate is at a higher potential than the source. See Figure 5 for a typical plot of drain current versus gate voltage. RF power FETs operate optimally with a quiescent drain current (IDQ ), whose value is application de- pendent. The MRF5015 was characterized at IDQ = 100 mA, which is the suggested value of bias current for typical ap- plications. For special applications such as linear amplifica- tion, IDQ may have to be selected to optimize the critical parameters. The gate is a dc open circuit and draws essentially no cur- rent. Therefore, the gate bias circuit may generally be just a simple resistive divider network. Some special applications may require a more elaborate bias system. GAIN CONTROL Power output of the MRF5015 may be controlled to some degree with a low power dc control signal applied to the gate, thus facilitating applications such as manual gain control, ALC/AGC and modulation systems. Figure 4 is an example of output power variation with gate–source bias voltage with Pin held constant. This characteristic is very dependent on frequency and load line.

MRF5015MOTOROLA RF DEVICE DATA AMPLIFIER DESIGN Impedance matching networks similar to those used with bipolar transistors are suitable for the MRF5015. For exam- ples see Motorola Application Note AN721, “Impedance Matching Networks Applied to RF Power Transistors.” Both small–signal S–parameters and large–signal impedances are provided. While the S–parameters will not produce an exact design solution for high power operation, they do yield a good first approximation. This is an additional advantage of RF power MOSFETs. Since RF power MOSFETs are triode devices, they are not unilateral. This coupled with the very high gain of MRF5015 yield a device quite capable of self oscillation. Stability may be achieved by techniques such as drain loading, input shunt resistive loading, or output to input feedback. Different stabilizing techniques may be required depending on the desired gain and bandwidth of the application. The RF test fixture implements a parallel resistor and capacitor in series with the gate to improve stability and input impedance Q. Two port stability analysis with the MRF5015 S–parame- ters provides a useful tool for selection of loading or feed- back circuitry to assure stable operation. See Motorola Two–Port Parameters,” for a discussion of two port network theory and stability.

CASE 319–07 ISSUE M 0.965 0.355 0.230 0.115 0.102 0.075 0.160 0.004 0.090 0.225 0.125 0.985 0.375 0.260 0.125 0.114 0.085 0.170 0.006 0.110 0.241 0.135 24.52 9.02 5.85 2.93 2.59 1.91 4.07 0.11 2.29 5.72 3.18 25.01 9.52 6.60 3.17 2.90 2.15 4.31 0.15 2.79 6.12 3.42 MM MIN MIN MAX MAX INCHES MILLIMETER DIM A B C D E F H J K L N Q NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: INCH. 0.725 BSC 18.42 BSC SEATING PLANE IDENTIFICATION NOTCH 12 3 456 F J B H E K L 0.15 (0.006) T A NM -A- -N- -T- Q 2 PL D 2 PL MM0.38 (0.015) T A NM MM0.38 (0.015) T A NM C PIN 1. SOURCE (COMMON) 2. GATE (INPUT) 3. SOURCE (COMMON) 4. SOURCE (COMMON) 5. DRAIN (OUTPUT) 6. SOURCE (COMMON) STYLE 3: How to reach us: USA / EUROPE : Motorola Literature Distribution; JAPAN : Nippon Motorola Ltd.; Tatsumi–SPD–JLDC, Toshikatsu Otsuki, P.O. Box 20912; Phoenix, Arizona 85036. 1–800–441–2447 6F Seibu–Butsuryu–Center, 3–14–2 Tatsumi Koto–Ku, Tokyo 135, Japan. 03–3521–8315 INTERNET : http://Design–NET.com 51 Ting Kok R oad, Tai Po, N.T., Hong Kong. 852–26629298 Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. “Typical” parameters can and do vary in different applications. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. Motorola does not convey any license under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that Motorola was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer. MRF5015/D /C0042/C0077/C0082/C0070/C0053/C0048/C0049/C0053/C0047/C0068/C0042