...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Circuits and systems >High Accurate Howland Current Source: Output Constraints Analysis
【24h】

High Accurate Howland Current Source: Output Constraints Analysis

机译：高精度Howland电流源：输出约束分析

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Howland circuits have been widely used as powerful source for exciting tissue over a wide frequency range. When a Howland source is designed, the components are chosen so that the designed source has the desired characteristics. However, the operational amplifier limitations and resistor tolerances cause undesired behaviors. This work proposes to take into account the influence of the random distribution of the resistors in the modified Howland circuit over the frequency range of 10 Hz to 10 MHz. Both output current and impedance of the circuit are deduced either considering the operational amplifiers parameters or not. The probability density function due to small changes in the resistors of the circuit was calculated by using the analytical modeling. Results showed that both output current and impedance are very sensitive to the resistors variations. In order to get higher output impedances, high operational amplifier gains are required. The operational amplifier open-loop gain increases as increasing the sensitivity of the output impedance. The analysis done in this work can be used as a powerful co-adjuvant tool when projecting this type of circuit in Spice simulators. This might improve the implementations of practical current sources used in electrical bioimpedance.
机译：Howland电路已被广泛用作在很宽的频率范围内激发组织的强大信号源。在设计Howland光源时，应选择组件，以使设计的光源具有所需的特性。但是，运算放大器的局限性和电阻容差会导致不良行为。这项工作建议考虑在10 Hz至10 MHz频率范围内，改进的Howland电路中电阻器的随机分布的影响。不论是否考虑运算放大器参数，都可以得出电路的输出电流和阻抗。通过使用解析模型来计算由于电路的电阻器的微小变化引起的概率密度函数。结果表明，输出电流和阻抗都对电阻变化非常敏感。为了获得更高的输出阻抗，需要高运算放大器增益。运算放大器的开环增益随着输出阻抗灵敏度的增加而增加。在Spice模拟器中投影此类电路时，可以将这项工作中完成的分析用作强大的辅助工具。这可以改善用于生物电阻抗的实际电流源的实现。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号