A high-voltage, high-current CMOS pulse generator ASIC for deep brain stimulation

A high-voltage, high-current pulse generator ASIC based on 0.35-εm high-voltage CMOS technology is presented. The chip has eight independently-controlled biphasic output channels that can generate either current- or voltage-controlled pulses. The output driver is capable of delivering current up to 1.26 mA or 5.04 mA and voltage up to 2.36 V or 9.45 V; all with 6-bit resolution. The stimulation frequency can be adjusted between 3 Hz to 5 kHz, while pulse width can vary from 20 µs to 640 εs in 20 εs steps for 100-kHz clock frequency. The timing parameters can be adjusted further by varying the clock frequency. These parameters, including pulse phase, can be programmed independently in each channel to allow different waveform generation. The foregoing provides an on-chip solution for an arbitrary function generator that can be monolithically fabricated with the rest of the circuitry. Based on its configuration this chip is an ideal solution for deep brain stimulation (DBS) electrode for targeted stimulation through current steering.