MRF275L

MRF275L MACOM | Alldatasheet

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N–Channel Enhancement–Mode Designed for broadband commercial and military applications using single ended circuits at frequencies to 500 MHz. The high power, high gain and broadband performance of this device makes possible solid state transmitters for FM broadcast or TV channel frequency bands.

• Guaranteed Performance @ 500 MHz, 28 Vdc Output Power — 100 Watts Power Gain — 8.8 dB Typ Efficiency — 55% Typ
• 100% Ruggedness Tested At Rated Output Power
• Low Thermal Resistance
• Low Crss — 17 pF Typ @ VDS = 28 Volts MAXIMUM RATINGS Rating Symbol Value Unit Drain–Source Voltage VDSS 65 Vdc Gate–Source Voltage VGS ± 20 Vdc Drain Current — Continuous ID 13 Adc Total Device Dissipation @ TC = 25°C Derate above 25°C PD 270 1.54 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 qJC 0.65 °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 = 50 mA) V(BR)DSS 65 — — Vdc Zero Gate Voltage Drain Current (VDS = 28 V, VGS = 0) IDSS — — 2.5 mAdc Gate–Body Leakage Current (VGS = 20 V, VDS = 0) IGSS — — 1.0 mAdc NOTE – CAUTION – MOS devices are susceptible to damage from electrostatic charge. Reasonable precautions in handling and packaging MOS devices should be observed. MRF275L

100 W, 28 V, 500 MHz

N–CHANNEL BROADBAND RF POWER FET CASE 333–04, STYLE 2 D G S REV2 Order this document by MRF 275L/DSEMICONDUCTOR TECHNICA L D ATA

Figure 1. 500 MHz Test Circuit

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

500 MHz

400 MHz

Figure 10. Series Equivalent Input/Output Impedance operates at a given output power, voltage and frequency.

Table 1. Common Source S–Parameters (VDS = 12.5 V, ID = 4.5 A)

Table 1. Common Source S–Parameters (VDS = 12.5 V, ID = 4.5 A) (continued) Table 2. Common Source S–Parameters (VDS = 24 V, ID = 4.5 A)

Table 2. Common Source S–Parameters (VDS = 24 V, ID = 4.5 A) (continued) Table 3. Common Source S–Parameters (VDS = 28 V, ID = 4.5 A)

Table 3. Common Source S–Parameters (VDS = 28 V, ID = 4.5 A) (continued)

RF POWER MOSFET CONSIDERATIONS MOSFET CAPACITANCES The physical structure of a MOSFET results in capacitors between the terminals. The metal oxide gate structure deter- mines the capacitors from gate–to–drain (Cgd), and gate–to– source (Cgs). The PN junction formed during the fabrication of the FET results in a junction capacitance from drain–to– source (Cds). These capacitances are characterized as input (Ciss), out- put (Coss) and reverse transfer (Crss) capacitances on data sheets. The relationships between the inter–terminal capaci- tances and those given on data sheets are shown below. The C iss 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 zero volts at the gate. In the latter case the numbers are lower. However, neither method represents the actual operat- ing conditions in RF applications. Cgd GATE SOURCE Cgs DRAIN Cds Ciss = Cgd + Cgs Coss = Cgd + Cds Crss = Cgd DRAIN CHARACTERISTICS One figure of merit for a FET is its static resistance in the full–on condition. This on–resistance, VDS(on), occurs in the linear region of the output characteristic and is specified un- der specific test conditions for gate–source voltage and drain current. For MOSFETs, VDS(on) has a positive temperature coefficient and constitutes an important design consideration at high temperatures, because it contributes to the power dissipation within the device. GATE CHARACTERISTICS The gate of the FET is a polysilicon material, and is electri- cally isolated from the source by a layer of oxide. The input resistance is very high — on the order of 109 ohms — result- ing in a leakage current of a few nanoamperes. Gate control is achieved by applying a positive voltage slightly in excess of the gate–to–source threshold voltage, VGS(th). Gate Voltage Rating — Never exceed the gate voltage rating. Exceeding the rated VGS can result in permanent damage to the oxide layer in the gate region. Gate Termination — The gates of these devices are essentially capacitors. Circuits that leave the gate open–cir- cuited or floating should 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. Using a resistor to keep the gate–to–source impedance low also helps damp transients and serves another important 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. HANDLING CONSIDERATIONS When shipping, the devices should be transported only in antistatic bags or conductive foam. Upon removal from the packaging, careful handling procedures should be adhered to. Those handling the devices should wear grounding straps and devices not in the antistatic packaging should be kept in metal tote bins. MOSFETs should be handled by the case and not by the leads, and when testing the device, all leads should make good electrical contact before voltage is ap- plied. As a final note, when placing the FET into the system it is designed for, soldering should be done with a grounded iron. DESIGN CONSIDERATIONS The MRF275L is a RF power N–channel enhancement mode field–effect transistor (FETs) designed for HF, VHF and UHF power amplifier applications. M/A-COM FETs feature a vertical structure with a planar design. M /A-COM Application Note AN211A, FETs in Theory and Practice, is suggested reading for those not familiar with the construction and characteristics of FETs. The major advantages of RF power FETs include high gain, low noise, simple bias systems, relative immunity from thermal runaway, and the ability to withstand severely mis- matched loads without suffering damage. Power output can be varied over a wide range with a low power dc control sig- nal. DC BIAS The MRF275L is an enhancement mode FET and, there- fore, does not conduct when drain voltage is applied. Drain current flows when a positive voltage is applied to the gate. RF power FETs require forward bias for optimum perfor- mance. The value of quiescent drain current (IDQ ) is not criti- cal for many applications. The MRF275L was characterized at IDQ = 100 mA, each side, which is the suggested minimum value of IDQ . For special applications such as linear amplifi- cation, IDQ may have to be selected to optimize the critical parameters. The gate is a dc open circuit and draws no current. There- fore, the gate bias circuit may be just a simple resistive divid- er network. Some applications may require a more elaborate bias system. GAIN CONTROL Power output of the MRF275L may be controlled from its rated value down to zero (negative gain) by varying the dc gate voltage. This feature facilitates the design of manual gain control, AGC/ALC and modulation systems. REV2

CASE 333–04 ISSUE E D NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: INCH. STYLE 2: PIN 1. SOURCE 2. DRAIN 3. SOURCE 4. GATE SEATING PLANE L Q 2 PL MAM0.13 (0.005) B MT –A– K K –B–P F G H –T– NJ E C DIM MIN MAX MIN MAX MILLIMETERS INCHES A 0.965 0.985 24.51 25.02 B 0.390 0.410 9.91 10.41 C 0.250 0.290 6.73 7.36 D 0.190 0.210 4.83 5.33 E 0.095 0.115 2.42 2.92 F 0.215 0.235 5.47 5.96 G 0.725 BSC 18.42 BSC H 0.155 0.175 3.94 4.44 J 0.004 0.006 0.10 0.15 K 0.195 0.205 4.95 5.21 L 0.740 0.770 18.80 19.55 N 0.415 0.425 10.54 10.80 P 0.390 0.400 9.91 10.16 Q 0.120 0.135 3.05 3.42 Specifications subject to change without notice. n North America: Tel. (800) 366-2266, Fax (800) 618-8883 n Asia/Pacific: Tel.+81-44-844-8296, Fax +81-44-844-8298 n Europe: Tel. +44 (1344) 869 595, Fax+44 (1344) 300 020 Visit www.macom.com for additional data sheets and product information. R EV2