Health-care sensor interface IC integrates NFC energy harvesting

EnSilica has developed an ultra-low-power sensor interface IC for monitoring vital signs in wearable health-care and medical devices. The ENS62020 is among the first to integrate an NFC energy harvesting circuit, making it suitable for both battery-powered and battery-less systems.

The sensor interface IC is designed for low-power wearables that operate directly from a small battery or an NFC field to harvest power. Applications include home-use and single-use medical sensors – from oximeters to smart patches – as well as wearable health-care sensors and fitness trackers.

The ENS62020 health-care sensor interface IC supports a variety of vital sign measurements. These include ECG, temperature, and differential capacitance, as well as optical signals, which are used to track heart rate (PPG), oxygen saturation (SpO2), glucose levels, and for near-infrared spectroscopy.

Health-care sensor interface IC integrates NFC energy harvesting

EnSilica ENS62020 block diagram. Click for a larger image. (Source: EnSilica)

The IC is designed to work with an edge processor or a communication device, and integrates two photodiode drivers/photodetector readouts and two differential ECG sensor channels suitable for 3-lead ECG with <1.6 µVrms noise levels. Other integrated features include a highly sensitive capacitive sensor channel, a temperature sensor with <0.15oC resolution (between 35-45oC), and a low-power ADC. The device consumes approximately 10-µA per sensor.

Due to the size and power-optimized design, the device is suited to disposable medical devices and patches as well as sports and fitness devices, said EnSilica. It also can be used for MEMS sensing interfaces.

The ENS62020 is built ON a modular IC design that enables customization and a product-optimized ASIC, which also helps to reduce time to market, said the company.

Samples of the sensor interface IC, housed in a plastic QFN 32-pin package, will be available in June. An evaluation kit with board and demonstration software will follow in July. The evaluation kit will include a NucleoSTM32 host board with a USB connection, 3.3-V supply and external clocks, and an interrupt driven readout for data streaming. Other features include a SFH7072 optical sensor, headphone jack for three ECG electrodes, connector for the NFC antenna, and control software and GUI. Options include USB power and custom SPI host and a capacitive bridge.