描述 Description

Medical Surge Protection Device, 7-Terminal, Pacemaker?ApplicationMicrosemi’s surge protection devices protect implantable medical devices from damage resulting from an external defibrillation event. The ZL70571, ZL70572, ZL70573, ZL70574, and ZL70588 form a family of high-performance surge protection devices for implantable medical electronics. Optimized for fast turn-on and extremely low leakage current, the ICs ensure high performance and reliability, as well as an easy route to compliance with the EN-45502 and EN-50061 specifications. Microsemi’s family of surge protection devices includes variants to support a range of application requirements for number of terminals and operating voltage.Key FeaturesEnhanced PerformanceExtremely fast turn-onExtremely low leakage allows terminals to be connected in parallel to the device being protectedEases DesignVariants with five, six, or seven terminals support a range of application requirementsVery small size supports trend for miniaturizationPackaging and AvailabilityPackage: Solder bumped die or wire-bondable bare dieSuperior QualityQA procedures based on MIL-PRF-38535Wafer-level traceabilityLot acceptance testing includedProtects Implantable Medical?Devices from Damage Resulting from an?External?Defibrillation?EventIn Response to the Voltage Rising to a Dangerous Level, the Surge Protection Device Rapidly Turns?On and Shunts the CurrentImplantable medical electronics such as pacemakers and neurostimulators are used to treat a wide range of illnesses including bradycardia, tachycardia, Parkinson’s disease, chronic pain, and muscle spasticity. To maintain reliability, these implantable devices must be able to withstand electrical surges, such as those caused by medical treatments like external defibrillation.As a typical example, the diagram shown below of a dual-chamber pacemaker demonstrates how a typical surge protection device protects sensitive circuitry from transient currents. Designed with extremely low leakage during normal pacing voltages, the terminals of the surge protection device are connected in parallel with those of the protected pacemaker pins.When the voltage between the terminals rises to a dangerous level, the device rapidly turns on and shunts the current.? Surge suppression occurs through a self-triggering thyristor-diode, coupled with a diode between each branch-input and common node. When a transient current is forced between two terminals, the positive terminal is clamped to the common node by the diode of one branch, and the negative terminal to the forward voltage of the thyristor-diode on the other branch. The low on-voltage of the thyristor ensures that voltage remains at a safe value during the transient.Extremely fast turn-on and low leakage current eases compliance with regulations EN-45502 for active implantable medical devices, and EN-50061 for implantable cardiac pacemakers.