In multi-electrode arrays (MEAs), for electrical recording and electrical stimulation, high voltage (HV) switches are employed to build an analog multiplexer to conduct either a HV stimulation signal from the pulse generator circuit to an electrode or a low-voltage noise-sensitive signal from the electrode to a recording stage. In this brief, a new circuit structure is proposed for HV switches that significantly improves their switching speed, reduces their power dissipation, and also employs a minimum number of bulky HV devices. In order to reduce the transition time of the proposed switch without consuming a large amount of power, during the transition time that the switch is turning on/off, a large current flows through the driver circuit of the switch to turn the switch on/off rapidly; however, after the transition times, this current is significantly reduced to save power. Based on the proposed HV switch, a multiplexer structure has been implemented in 25-V, 0.18- μm CMOS IC technology and the measurement results prove its efficacy. Supplied with 25 V and operating with 300 nA current consumption, this switch swings over 20 V with a relatively constant on-resistance of 100Ω and features a 80 ns transition time.

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Large-array resistive sensors have found a variety of applications from industrial instrumentation to medical wearable applications. In such large-array sensors, several non-idealities limit the accuracy of the readout circuit. In this paper, after analyzing the crosstalk error caused by the input offset voltage and input bias current of the operational amplifier, a novel double-sampling technique is proposed to considerably reduce the error. Spice simulation results of a 20 × 20 array confirm that for a 1-MQ resistance, the proposed technique can decrease the maximum measureable relative error from 20% to 0.089%. Furthermore, the measurement results of a 20 × 20 array confirm that for a resistance value of 19 MQ being measured, the proposed technique can reduce the error from 84% to 0.69%.@en