Over the years, Microdul AG has gained experience in the field of medical applications, in particular neuromuscular stimulation. Two ASIC concepts for neurostimulation ASICs that can be implemented in different technologies are presented below.
The low voltage chip MS1031 is realized on Microdul's semicustom array MD500 and offers the possibility of monophasic and biphasic stimulation pulses in bipolar mode for voltages up to 8V. The amplitude of the pulses can be programmed up to 2.55mA with a resolution of 10µA. The programmable time sequences are realized with an internal or external oscillator of 100kHz.
The high voltage chip MS1032 can generate monophasic and biphasic stimulation pulses in monopolar mode for voltages up to 18V. Charge balancing can be realized with or without slow reversal (4:1). The amplitude of the pulses can be programmed up to 2.55mA with a resolution of 10uA. The programmable time sequences are realized with an internal or external oscillator of 100kHz. Overcurrent and undercurrent protection is part of the safety concept. The chip offers a switch matrix where the current sink/source channels and analog peripheral inputs can be flexibly assigned to the outputs of the switch matrix.
Feature Overview
Type | MS1031 | MS1032 | ||
Main feature | 8-channel programmable current pulse generator | 8-channel current sink/source for neuromuscular stimulation | ||
Channel outputs | 8 | 16 | ||
Pulse modes | Monophasic Biphasic |
Monophasic Biphasic Biphasic with slow reversal (4:1) |
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Programable pulse parameters | Timing Sequence | Timing Sequence | ||
Pulse polarity | Anodic + Cathodic | Anodic + Cathodic | ||
Stimulation types | Bipolar | off / low / high | ||
Max. stimulation current per channel (* more channels can be connected in parallel for higher current output) |
2.55mA | 2.55mA | ||
Programming resolution of the current | 10uA | 10uA | ||
Current sink to source amplitude ratio | 1:1 | 1:1 4:1 |
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Output switch matrix | no | yes | ||
Overcurrent and undercurrent protection | no | yes | ||
Internal oscillator | yes | yes | ||
External clock input | yes | yes | ||
Voltage reference | 1.25V | 1.25V | ||
Shutdown input (safety feature) | yes | yes | ||
Cascading | yes | no | ||
10 MHz SPI interface | x | yes | ||
Operating voltage range | 2.2V to 3.3V | 1.8V to 4.5V | ||
Operating temperature range | +10°C to +50°C | +10°C to +50°C | ||
Packaging | Various packaging options (die, flip-chip, packaged) | Various packaging options (die, flip-chip, packaged) | ||
Concept datasheet | Link | Link |