An Integrated Circuit for Biphasic Pulse Generator with Variable Parameters

Abstract

A biphasic pulse generator integrated circuit (IC) was designed, and the parameters of the generated pulses such as pulse rate, duration, and amplitude were adjusted to the desired values by using the time-varying differences of two inputs of the operational amplifier integrated on the IC. The chip was fabricated with the MagnaChip /SK Hynix CMOS 0.35 mu m process, which allowed a maximum pulse amplitude of 3.3 V. In addition, it included a transformer that allowed the IC to rectify the amplitude modulated (AM) input with a 1 Ghz carrier and provide the supply voltage to generate the pulses. The whole size of the full system was 441.5 mu m x527.8 mu m, and the system successfully generates biphasic pulses up to 1.2 kHz using the RF signal. This circuit can be used to generate biphasic pulses with variable parameters for distributed neural interfaces, and to provide scan voltages for potentiostat applications such as in the Fast Scan Cyclic Voltammetry (FSCV). In addition, this IC with an integrated transformer suggests that a wireless electroanalytical system on a chip can be achieved as a future work.