Microsemi Corp. has announced four additions to its DRF family of RF MOSFET drivers and hybrid RF driver/MOSFETs.
Designated the DRF200 switch mode driver, the DRF1201 and DRF1202 single-channel hybrids, and the DRF1300 dual channel hybrid, the new devices are targeted at 2 to 50 MHz, high power, high voltage Class D and E RF generators that are used extensively in plasma generation, CO2 laser excitation, switch mode power amplifiers, pulse generators, ultrasound transducer drivers and acoustical optical modulators.
• Drives up to 3 nF MOSFET gate capacitance (DRF 200)
• Up to 1100 W pulsed output power (DRF1201)
• Low cost, high power cycle capable flangeless packages
• Up to 50 MHz operation (50 Ohm load)
• 165 V operation/1000 V BV (DSS)
• Class D and E operation
• Maximized safe operating area (SOA)
• High load mismatch tolerance
• Superior thermal stability
The DRF200 switch mode driver has been optimized to drive 500 V and 1000 V RF power MOSFETs. It is able to drive RF MOSFETs gates having greater than 3 nF capacitance to 15 V at 15 MHz. Previously, driving such high voltage MOSFETs at RF frequencies has been difficult because of their large gate capacitance.
To further optimize system performance, the DRF1201 and DRF1202 single-channel hybrids integrate the driver, bypass capacitors and either 500 V or 1000 V RF MOSFETs into a single package. This maximizes performance by minimizing transmission line parasitics between the driver, bypass capacitors and MOSFETs.
The DRF1300 hybrid contains two independent channels, each containing a driver and a 1,000V RF MOSFET in a push-pull configuration. All DRF devices feature a proprietary anti-ring function to eliminate cross conduction in bridge or push-pull topologies. All DRF parts can be externally selected in either an inverting or non-inverting configuration, except for the DRF200 (non-inverting only).
The DRF hybrids enable a new generation of low cost, high density Class D and E RF amplifiers operating at higher voltages and higher load impedances. The new 1000 V DRFs can easily operate at 125 V, allowing load impedances of 50 Ohms. The higher impedance allows simpler transformers and combiners.
Paralleled devices can now operate into reasonable and convenient impedances. The increased operating voltage also lowers the DC current required for any given power output, increasing efficiency and reducing the size, weight and cost of other system components.
The DRF flangeless package offers low thermal resistance and lower cost compared to ceramic packages having a copper tungsten flange. The RF flangeless package design uses an air cavity and closely matched CTEs that maximize system reliability by alleviating stress during power cycling. Typical applications have been demonstrated beyond one million cycles with a power density of 700 W/square inch.
Samples and prototype production quantities are available now. At quantities of 100 pieces, the unit price for the DRF200 is $29.24.