Design considerations for low-power ADC for retinal prosthesis applications

Retinal prostheses have great potential in helping restore vision in patients suffering age-related macular degeneration and retinitis pigmentosa. Power consumption is a major problem for implanted devices. Biomedical implant researchers are investigating suitable low-power architectures for future implant systems. For this reason, the design of ultra-low power interfaces, especially analog-to-digital converters is very important. A successive approximation analog-to-digital converter (ADC) has a simple and flexible architecture that makes it well-suited for systems utilizing wireless power transfer and operation below 1 Volt. This paper reviews power-efficient ADC techniques suitable for biomedical implant devices.