IEEE RFID-TA 2021

A UHF RFID to I²C Bridge IC with Configurable Power Storage Unit for Flexible RFID Sensor Applications. Jun Tan¹, Muralikrishna Sathyamurthy¹, Hani Abdullah¹, Jonathan Gamez¹, Bjoern Bieske¹, Benjamin Saft¹, Martin Grabmann¹, Jacek Nowak², Sylvo Jäger², and Eric Schäfer¹

¹IMMS Institut für Mikroelektronik- und Mechatronik-Systeme gemeinnützige GmbH (IMMS GmbH), Ilmenau, Germany; ²Micro-Sensys GmbH, Erfurt, Germany

Abstract: This paper presents the design of a fully passive 865 MHz to 867 MHz UHF RFID to I²C Bridge IC with an integrated I²C master for external digital sensor communications. To provide energy for external devices operation such as sensors, microcontrollers and memories, a Power Storage Unit (PSU) is directly integrated within the IC with an external capacitor as an energy storage element. Hence for communicating with external devices, the IC requires no additional power management components. Additionally, the on-chip I²C master eliminates the need for external microcontroller, thus making the system more energy-efficient and well suited for ultra-low power (ULP) sensing applications requiring battery free operation. The results show that this IC dynamically supplies an external non-volatile memory and a multi-sensor with 1.8 V output voltage and is capable of handling a dynamic load current of up to 1 mA required for multi-sensor readout operation. The memory and the multi-sensor are configured individually for timing and communications, while the sensor data is readout by RFID reader successfully. The chip is fabricated in a standard 0.18 μm SOI CMOS technology and its achieved performance are demonstrated in this paper in combination with a high-performance commercial-of-the-shelf sensor capable of measuring air temperature, humidity, and pressure.