X- and gamma-ray hardness of floating-gate EEPROM technology as applied to implantable medical devices
X- and gamma-ray hardness of floating-gate EEPROM technology as applied to implantable medical devices
复制标题
应用于植入式医疗设备的浮栅 EEPROM 技术的 X 射线和伽马射线硬度
DOI：
10.1109/6144.796541
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发表时间：
1999
影响因子：
--
通讯作者：
L. Stotts
中科院分区：
文献类型：
--
作者：
D. Prutchi;J. Prince;L. Stotts
越来越需要在植入式医疗装置中包含非易失性存储器，以便存储产品标识、操作参数、校准信息以及患者和诊断数据。然而，由于应用程序的关键性质，数据保留可靠性至关重要。在非易失性记忆的情况下，一个关注的来源是将其暴露于电离辐射视为对患者进行诊断或治疗程序的结果。本文在具有代表性的现代电可擦可编程只读存储器（Atmel 24C64）上进行了X射线和伽马射线的实验和计算。在10个无偏和5个偏DTU中，没有观察到150 kVp x射线引起的瞬态扰动，总剂量为200 rad(Si)，最大可达到27 rad(Si)/s。未偏压部分没有失败，平均总剂量为40.9克拉（Si）。观察到的无偏零件的最低失效水平为30.0克拉（Si）。在偏置部分，读取模式工作电流随着总剂量的增加而增加，从暴露于30克拉（Si）时的47 /spl mu/ a增加到385 /spl mu/ a。暴露于Co/sup 60/ γ射线的10个无偏零件的平均最高无故障水平为36.9克拉（Si）， sigma为2.3。5次偏测失败平均发生在27.84 krad(Si)， sigma为2.42。对这些数据的分析，并与最大治疗光子辐射剂量进行比较，表明漂浮门EEPROM技术在医疗诊断和治疗环境中典型的光子电离辐射暴露中是可靠的。
There is a growing need for the inclusion of nonvolatile memory within implantable medical devices in order to store product identification, operating parameters, calibration information, as well as patient and diagnostic data. Due to the critical nature of the application however, the data retention reliability is of utmost importance. In the case of nonvolatile memories, a source of concern regards their exposure to ionizing radiation as the result of diagnostic or therapeutic procedures performed on the patient. This paper reports on X- and gamma-ray experiments and calculations on a representative modern electrically erasable and programmable read-only memory (EEPROM) (Atmel 24C64). No transient upsets due to 150 kVp X-rays were observed in 10 unbiased and five biased DTU's up to the maximum achievable 27 rad(Si)/s for a total dose of 200 rad(Si). Unbiased parts had no failure to an average total-dose of 40.9 krad(Si). The lowest failure level observed for an unbiased part was 30.0 krad(Si). In the biased parts, the read-mode operating current increased as a function of total dose from 47 /spl mu/A prior to exposure to 385 /spl mu/A at 30 krad(Si). The mean highest no-failure level for 10 unbiased parts exposed to Co/sup 60/ gamma-rays was 36.9 krad(Si) with a sigma of 2.3. Five biased DUT failures occurred at a mean of 27.84 krad(Si) with a sigma of 2.42. The analysis of these data, in comparison to maximum therapeutic photon radiation doses suggest that floating-gate EEPROM technology is reliable in the presence of photon ionizing-radiation exposures typical of medical diagnostic and therapeutic environments.