Silicon-based RF capacitors in a 0201 footprint give designers another weapon in the effort to create smaller, more powerful wireless communications products. Developed by Vishay Intertechnology, the HPC0201A caps measure 0.024 by 0.012 by just 0.009 in. They best suit voltage-controlled oscillators, filter and matching networks, RF wireless communications modules, and medical applications like implantable defibrillators.
The single-contact configuration of the capacitors eliminates the "tombstoning" problem that plagues pc-board assembly when using conventional capacitors with wraparound terminations. They feature extremely stable capacitance values over a wide range of frequencies from 1 MHz to several gigahertz.
Also, the capacitors boast tight tolerances as low as ±1% or 0.05 pF, ultra-high self-resonant frequencies, and low parasitic inductance of about 0.035 nH. For example, a 39-pF capacitor offers twice the capacitance in one-fourth the space occupied by a conventional RF capacitor in an 0402 footprint. They operate from −55°C to 125°C.
The capacitors are available in 44 standard options ranging from 0.4 to 39 pF. They're rated for 6-, 10-, 16-, and 25-V operation. Temperature coefficient of capacitance is rated at 0 ±30 ppm/°C, and insulation resistance is 1011 Ω minimum. Devices with nonstandard capacitance values and lead-free solder are also available on request.
Samples of the silicon capacitors have a lead time of stock to 10 weeks. With ±2% tolerance, the capacitors cost $0.058 each in production quantities. Design kits are also available.Vishay Intertechnology Inc. www.vishay.com (610) 640-4903