Martin Wiessflecker

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State-of-the-art wireless sensor nodes are mostly supplied by batteries. Such systems have the disadvantage that they are not maintenance free because of the limited lifetime of batteries. Instead, wireless sensor nodes or related devices can be remotely powered. To increase the operating range and applicability of these remotely powered devices an(More)
State-of-the-art passive RFID tags are limited in terms of functionality and operating range due to the limited power that can be converted from the electromagnetic field. This is why state-of-the-art wireless sensor systems are mostly battery-based if a high operating range is required. The proposed ultralow-power on-chip sensor unit and off-chip sensor(More)
To increase the operating range and applicability of remotely powered devices an electro-magnetic energy harvester is developed in a 0.13 µm low cost CMOS technology. The presented system converts RF power to DC power to supply wireless sensor nodes, active transmitters or related systems with a power consumption up to the mW range. The chip includes(More)
This paper presents a bandgap reference capable of operating at supply voltages below 1V. In contrast to the vast majority of bandgap circuits the multiplication of the proportional to absolute temperature voltage is done by a switched capacitor network. Thus a reduced chip area is achieved. As a clock is needed for the switching, a relaxation oscillator is(More)
This paper presents a battery-less tire pressure monitoring system. Electro-magnetic field energy harvesting is utilized. The chip is also capable of RFID in a frequency range from 1MHz to 2.45GHz. The sensor data is transmitted either by an active transmitter at 868MHz or by employing the RFID feature. A bulk acoustic wave resonator is used as frequency(More)
This paper presents a successive approximation analog to digital converter with a configurable resolution of 8 or 11 bit. The resolutions are achieved by combining an 8 bit split capacitor array with a 3 bit resistive ladder allowing for a simpler layout and good power efficiency. Configurable buffers are included and enable a wide range of operation(More)
A wireless self-sufficient human body temperature monitoring system was designed using a 130 nm CMOS standard process. This miniaturized sensor grain enables significant cost advantages and impresses with its high level of integration. The RFID communication protocol ensures compatibility with state-of-the-art smart phones and tablets, thus facilitating(More)
The combination of UWB Impulse Radio with RFID technology is proposed, implemented and analysed in this paper. For future RFID technologies, inexpensive and power efficient transceivers on the tag side are necessary for the application of Smart Dust and the Internet of Things. Therefore, we have designed and manufactured two silicon prototypes of a(More)
This paper presents an ultra-low power voltage regulator used for low power wireless sensor nodes. As the input conditions for these types of regulators can be quite different in terms of voltage range and transient speed, the introduced architecture is designed to be almost insensitive to these variations. Even if the pass device is formed by an NMOS(More)