Microsemi Corp. (Santa Ana, CA) announced a new high-voltage MOSFET for implantable cardio defibrillator (ICD) applications that is 40 percent smaller than those currently available. Designated the MSAFA1N100D, the new device is the first to be developed jointly by Microsemi and Advanced Power Technology (APT, Bend, OR).The Microsemi device will be used as an overvoltage protection circuit in the next generation of implantable cardio defibrillators. These implants must withstand high voltages induced either by the ICD itself or by external defibrillation in emergency room and other treatment procedures.New types of multiple-phase high voltage therapies are driving broader use of implantable cardio defibrillators, which can require 10 MOSFETs each. It is estimated that this market will grow at an annual rate of more than 20 percent , with nearly 70,000 such implants last year alone. Although much smaller than prior implantable MOSFETs, the new Microsemi device provides equivalent electrical performance, according to the firm. In addition to meeting the required specifications of 1,000V and 13.5 Ohms at body temperatures (37C), Microsemi's new device is claimed to provide ICD designers with the ability to reduce battery drain by taking advantage of the MSAFAIN100D's gate charge spec of less than 20nC. Another version of the MSAFA1N100D was developed simultaneously for Microsemi's upcoming Powermite 3 package. This version uses a specially developed solderable contact surface, a first in MOSFET design, according to Microsemi.