A 365mV, 13nW CMOS-only energy harvested reference voltage for RFID applications in 40nm technology

• Published in: 2019 XXXIV Conference on Design of Circuits and Integrated Systems (DCIS) pp. 1 - 6
• Main Authors: Bahramali, Asghar, Lopez-Vallejo, Marisa, Barrio, Carlos Lopez
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.11.2019
• Subjects: Charge pump; Charge pumps; CTAT; Logic gates; Power demand; pre-regulator; PTAT; Radiofrequency identification; Reference voltage; Regulation; Temperature dependence; Temperature sensors
• ISSN: 2640-5563
• DOI: 10.1109/DCIS201949030.2019.8959909

In this work a low voltage low power reference voltage with the aid of only normal CMOS devices is designed and simulated in a commercial 40nm technology. It is mainly intended for applications where having the access to the main power network is very unlikely or impossible. The proposed circuit takes advantage of an embedded Dickson charge pump that converts an RFID (radio frequency identification) harvested input voltage of 800mV amplitude to a DC level of 2V. In this way not only the needed supply voltage is provided for the circuit but also a new strategy is used to make it temperature resilient. Here the positive temperature behavior of the Dickson charge pump is employed to compensate the negative temperature coefficient voltage of the gate-source of the diode connected CMOS devices. In this manner the circuit becomes not only self biased but also temperature invariant. In this study a 365mV reference voltage with 13.3nW power consumption is presented. The circuit has a PSR (Power supply rejection) of -73dB with 7.5% line regulation. The temperature coefficient (TC) of the circuit in the temperature range of -55°C to 125°C is 53ppm/°C and its die size, including the charge pump, is 397μm 2 . The effect of process variation on the reference voltage from its nominal value is ±16% without using trimming.