Defibrillation and ESD protection for medical designs with 100x less leakage current

March 03, 2017 // By Nick Flaherty
Maxim Integrated Products has developed an ESD protection device for medical designs that brings the leakage current down to 10pA.

The MAX30034 is aimed at medical equipment such as defibrillators as well as ECG diagnostics and monitoring systems to protect against defibrillation pulses and electrostatic discharge (ESD). Designers of such systems face a challenge as the ECG input amplifiers must withstand high-voltage pulses for cardiac resuscitation that can easily damage the sensitive electronic circuitry which captures the millivolt level heart signals. Preventing this damage has required a three-layer, multi-component approach combining a per-channel gas-discharge tube (GDT) and/or transient-voltage suppression (TVS) device, as well as ESD-protection diodes. Further, leakage current (a critical parameter) is relatively high, at about 1-2nA.

Maxim's four-channel MAX30034 uses an innovative topology to absorb and harmlessly redirect these high-energy pulses away from sensitive circuitry. The device needs only two external pairs of resistors for each channel to provide design simplicity, smaller overall size, and lower leakage current, replacing the primary-level GDTs and/or TVSs, as well as secondary-level ESD diodes which are the conventional solutions for mandated circuit protection. The device can withstand over 100,000 defibrillation pulses without failure and still maintain a leakage current under 10pA, 100x less than GDT/TVS-based approaches.

“Customers need innovative, tightly focused components like this,” said Andrew Baker, Executive Director for Industrial and Healthcare at Maxim Integrated. “It completely changes the component solution to the long-standing challenge of protecting the medical device against a defibrillation pulse.”

The MAX30034 is priced at $3.40 and an evaluation kit is available for $25.

For more information visit:  bit.ly/MAX30034