“Wireless” now applies to a growing array of applications, including cell phones, broadband, microwave and satellite communications, RFID tags, security, medical and automotive electronics. The vast majority of wireless devices are battery-powered. Although there is growing interest in super capacitors and energy harvesting devices, batteries remain a more proven, reliable and cost-effective alternative for the vast majority of wireless applications. Advanced battery-operated wireless devices require cost-effective power management systems that are miniaturized, robust and reliable.