Making The Case For Well-Rounded Devices

July 17, 2006
In today's competitive wireless market, success is measured by providing solutions for customers rather than simply delivering "unprecedented performance" in a single area. For example, a new performance benchmark set by an RF power transistor will make ...

In today's competitive wireless market, success is measured by providing solutions for customers rather than simply delivering "unprecedented performance" in a single area. For example, a new performance benchmark set by an RF power transistor will make great headlines. But it will accomplish little else if it isn't accompanied by attributes that let customers put that performance to work. To be truly useful in a particular system, it must offer more than impressive P1dB or Psat "numbers." It also must be truly useful in a particular system, priced correctly, reliable, manufacturable in quantity, efficient, linear, and more—depending on the application. Today's OEMs need such "well-rounded devices."

In January, for example, Freescale introduced LDMOS RF power transistors for the 3.5-GHz WiMAX band. In doing so, it brought the low cost of silicon and performance comparable to GaAs to this band. Simply reaching 3.5 GHz was not enough, though. The devices also offer the very high linearity and efficiency required by the WiMAX specification. They are deliverable in volume and highly reliable. In short, they are well-rounded devices.

For Industrial, Scientific and Medical (ISM) applications, Freescale just introduced a family of LDMOS RF power transistors that deliver the required high output power (up to 300 W). In addition, these devices are housed in cost-effective over-molded plastic packages that significantly reduce cost. The family of six devices covers the HF/VHF band (10 to 450 MHz) and the 2.45-GHz band for applications like plasma generators, RF heating, magnetic resonance imaging (MRI), and even FM/VHF broadcast. Three of these devices are designed in the company's 50-V VHV6 process (rather than 28 V), which opens the door to higher overall performance and high power. Because LDMOS devices do not need isolation between source and drain (like VDMOS and bipolars), thermal performance is significantly improved over traditional devices.

Last month, Freescale introduced LDMOS high-power RF transistors that operate at 2 GHz. Although they are housed in cost-effective over-molded plastic packages, these transistors deliver performance comparable to air-cavity flange packages. This development offers a new way to reduce the cost of basestation amplifiers without sacrificing performance. All three achievements have one common element: They provide unique advantages for the people who use them, rather than simply achieving "unprecedented performance." In short, they're well-rounded devices. Freescale Semiconductor, Inc., 2100 E. Elliot Rd., Tempe, AZ 85284; Internet: www.freescale.com/rf.