Revistas
Revista:
SENSORS
ISSN:
1424-8220
Año:
2015
Vol.:
15
N°:
9
Págs.:
21554 - 21566
This paper presents an ultra low-power and low-voltage pulse-width modulation based ratiometric capacitive sensor interface. The interface was designed and fabricated in a standard 90 nm CMOS 1P9M technology. The measurements show an effective resolution of 10 bits using 0.5 V of supply voltage. The active occupied area is only 0.0045 mm(2) and the Figure of Merit (FOM), which takes into account the energy required per conversion bit, is 0.43 pJ/bit. Furthermore, the results show low sensitivity to PVT variations due to the proposed ratiometric architecture. In addition, the sensor interface was connected to a commercial pressure transducer and the measurements of the resulting complete pressure sensor show a FOM of 0.226 pJ/bit with an effective linear resolution of 7.64 bits. The results validate the use of the proposed interface as part of a pressure sensor, and its low-power and low-voltage characteristics make it suitable for wireless sensor networks and low power consumer electronics.
Revista:
TRANSACTIONS ON EMERGING TELECOMMUNICATIONS TECHNOLOGIES
ISSN:
2161-3915
Año:
2012
Vol.:
23
N°:
8
Págs.:
728 - 741
Power consumption is one of the most critical issues when designing low-cost electronic devices, such as sensing nodes in wireless sensor networks. To support their operation, such systems usually contain a battery; however, when the battery has consumed all its energy, the node (e.g. the sensor) must be retrieved and the battery replaced. If the node is located in a remote and non-accessible placement, battery replacement can become an expensive (and even impossible) task. This way, energy harvesting has emerged as a suitable alternative to supply low-power electronic systems, by converting ambient energy into electric power. Scavenged energy can be used to directly supply the circuits, or stored to be used when needed. This paper summarises the power needs of a general wireless sensor node and describes the main principles of most representative energy harvesting technologies. Copyright (c) 2012 John Wiley & Sons, Ltd.
Revista:
ADVANCES IN ELECTRICAL AND COMPUTER ENGINEERING
ISSN:
1582-7445
Año:
2012
Vol.:
12
N°:
1
Págs.:
15 - 18
The performance of a MEMS (Micro Electro-Mechanical Systems) Sensor in a RFID system has been calculated, simulated and analyzed. It documents the viability from the power consumption point of view- of integrating a MEMS sensor in a passive tag maintaining its long range. The wide variety of sensors let us specify as many applications as the imagination is able to create. The sensor tag works without battery, and it is remotely powered through a commercial reader accomplishing the EPC standard Class 1 Gen 2. The key point is the integration in the tag of a very low power consumption pressure MEMS sensor. The power consumption of the sensor is 12.5 mu W. The specifically developed RFID CMOS passive module, with an integrated temperature sensor, is able to communicate up to 2.4 meters. Adding the pressure MEMS sensor - an input capacity, a maximum range of 2 meters can be achieved between the RFID sensor tag and a commercial reader (typical reported range for passive pressure sensors are in the range of a few centimeters). The RFID module has been fabricated with a CMOS process compatible with a bulk micromachining MEMS process. So, the feasibility of a single chip is presented.