A wide range charge-balancing circuit using floating-gate transistors

Area of Science:

• Neuroscience
• Electrical Engineering
• Biomedical Engineering

Background:

• Electrical stimulation is crucial for neuroscience research and therapeutic applications.
• Existing methods for generating stimulation pulses face challenges in precision and efficiency.
• Developing advanced microelectronic circuits is key to improving neural interfaces.

Purpose of the Study:

• To design and implement a novel CMOS circuit for generating charge-balanced biphasic current pulses.
• To enable precise control over stimulation parameters like amplitude and duration.
• To enhance the efficiency and applicability of neural microstimulators.

Main Methods:

• A complementary metal-oxide-semiconductor (CMOS) circuit was designed.
• A synaptic current source was utilized to generate discharging current pulses.
• Programmable floating-gate transistors were employed for amplitude and duration control.
• The circuit was characterized for its stimulation output parameters.

Main Results:

• The designed CMOS circuit successfully produced charge-balanced biphasic current pulses.
• Stimulation current amplitude ranged from 100 picoamperes (pA) to 110 nanoamperes (nA).
• The pulse period was adjustable from 0.2 seconds (s) to 1 s.
• Programmable floating-gate transistors allowed precise control over pulse amplitude and duration.

Conclusions:

• The developed CMOS circuit provides an efficient and controllable method for neural electrical stimulation.
• The circuit's high stimulation efficiency makes it suitable for various neural microstimulator applications.
• This technology holds potential for advancing neural interface devices and neuroscience research.