IEEE Trans Biomed Circuits Syst. 2007 Sep;1(3):172-83. doi: 10.1109/TBCAS.2007.911631.
Large dc blocking capacitors are a bottleneck in reducing the size and cost of neural implants. We describe an electrode-stimulator chip that removes the need for large dc blocking capacitors in neural implants by achieving precise charge-balanced stimulation with <6 nA of dc error. For cochlear implant patients, this is well below the industry's safety limit of 25 nA. Charge balance is achieved by dynamic current balancing to reduce the mismatch between the positive and negative phases of current to 0.4%, followed by a shorting phase of at least 1 ms between current pulses to further reduce the charge error. On +6 and -9 V rails in a 0.7-mum AMI high voltage process, the power consumption of a single channel of this chip is 47 muW when biasing power is shared by 16 channels.
大容量的直流阻断电容器是减小神经植入物尺寸和成本的瓶颈。我们描述了一种电极刺激器芯片，通过实现精确的电荷平衡刺激，将直流误差降低到 <6 nA，从而消除了神经植入物中对大容量直流阻断电容器的需求。对于耳蜗植入患者，这远低于业界 25 nA 的安全限制。通过动态电流平衡实现电荷平衡，将正相和负相电流之间的不匹配减小到 0.4%，然后在电流脉冲之间进行至少 1 ms 的短路阶段，进一步减小电荷误差。在 0.7 微米 AMI 高压工艺的 +6 和 -9 V 轨上，当 16 个通道共享偏置功率时，该芯片单个通道的功耗为 47 μW。
