Ralf Brederlow

Prof. Ralf Brederlow

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Academic Career Length

24Years (2003-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 February 2018 in IEEE Journal of Solid-State Circuits
Verified
Journal Article
Closed access
FSFrancesco Santoro
Francesco Santoro
RKRudiger Kuhn
Rudiger Kuhn
NGNeil Gibson
Neil Gibson
NRNicola Rasera
Nicola Rasera
TTThomas Tost
Thomas Tost
RBRalf Brederlow
Ralf Brederlow
This paper presents a dc-dc converter for integration in the power management unit of an ultra-low power microcontroller. The converter is designed to significantly reduce the wake-up energy and startup delay of the supplied core. The use of a minimized output capacitor is the key factor to save the wake-up energy. The converter is buffered with only 56 nF and guarantees a stable output of 1.2 V with a voltage ripple smaller than 30 mV. The controller of the proposed dc-dc converter is based on a predictive peak current control that allows the system to control the energy transfer at extremely low power consumption. The proposed circuit is implemented in 130-nm CMOS technology with an area of only 0.14 mm 2 . It achieves a high conversion efficiency of 92.1% and a small quiescent current of 440 nA. It operates from 1.8 to 3.3 V with a maximum load of 2.65 mA.
10 May 2024 in Biosensors
Verified
Journal Article
Open access
PDF file
EKEva-Maria Korek
Eva-Maria Korek
RTReva Teotia
Reva Teotia
DHDavid Herbig
David Herbig
RBRalf Brederlow
Ralf Brederlow
Electrochemical impedance spectroscopy (EIS) is becoming more and more relevant for the characterization of biosensors employing interdigitated electrodes. We compare four different sensor topologies for an exemplary use case of ion sensing to extract recommendations for the design optimizations of impedimetric biosensors. Therefore, we first extract how sensor design parameters affect the sensor capacitance using analytical calculations and finite element (FEM) simulations. Moreover, we develop equivalent circuit models for our sensor topologies and validate them using FEM simulations. As a result, the impedimetric sensor response is better understood, and sensitive and selective frequency ranges can be determined for a given sensor topology. From this, we extract design optimizations for different sensing principles.
25 June 2003
Verified
Conference Paper
Closed access
HKH. Klauk
H. Klauk
MHMarcus Halik
Marcus Halik
UZU. Zschieschang
U. Zschieschang
GSGuenter Schmid
Guenter Schmid
WRW. Radlik
W. Radlik
WWW. Weber
W. Weber
We have fabricated organic thin film transistors (TFTs) and integrated circuits on flexible polymeric substrates with solution-processed polymer gate dielectric layers and obtained transistors with excellent electrical characteristics, as well as 5-stage ring oscillators with signal propagation delay as low as 22 /spl mu/sec per stage. To our knowledge, these are the fastest integrated circuits with organic transistors on flexible substrates reported to date.
22 December 2003
Verified
Conference Paper
Closed access
RBRalf Brederlow
Ralf Brederlow
SBS. Briole
S. Briole
HKH. Klauk
H. Klauk
MHMarcus Halik
Marcus Halik
UZU. Zschieschang
U. Zschieschang
WWW. Weber
W. Weber
Organic thin film transistors (TFTs) on flexible substrates are promising candidates for low-cost, low-performance electronic applications. Based on experimental data from the fastest organic circuits reported, the performance potential of organic TFTs is evaluated using a new physics-based compact model for the simulation of basic logic circuits.
17 April 2023 in IEEE Sensors Letters
Verified
Journal Article
Closed access
EKEva-Maria Korek
Eva-Maria Korek
EKEvanthia Kounoupioti
Evanthia Kounoupioti
RBRalf Brederlow
Ralf Brederlow
In this letter, a cost-effective, flexible, and fully printable potassium ion (K+) sensor is developed. The sensor consists of two interdigitated gold electrodes covered by a butylacrylate potassium ion-sensitive membrane (ISM). An impedimetric measurement method is chosen to eliminate the need for a reference electrode and to reduce signal drifting. We show the versatility and high reproducibility of the manufacturing process and present first measurement results. Our sensors achieve a sensitivity of 4.553 MΩ/(mmol/L) at 100 mHz and an accuracy of 1.8 mmol/L. The sensors exhibit low cross sensitivity toward sodium ions and show no signal drift.
1 May 2021
Verified
Conference Paper
Open access
LZLei Zhang
Lei Zhang
DBDavid Borggreve
David Borggreve
FVFrank Vanselow
Frank Vanselow
RBRalf Brederlow
Ralf Brederlow
The size of crossbar-like resistive multiplication accumulation (MAC) accelerators is restricted by parasitic interconnect resistances limiting the computation efficiency. In order to understand the impact of the interconnect (wire) resistance on the computation accuracy, this work proposes a modelling methodology for adapting the neural network weights regarding the weight error caused by wire resistance. Even more, this work investigates the maximal achievable crossbar size based on the proposed design variable "the minimal allowed weight error ratio Ron/Reqv" instead of using an iterative numerical method. Using the proposed method this work investigate the computation accuracy improvement through splitting the layer computation into multiple small crossbars. The result indicates that simply separating the computation into multiple small crossbar does not improve the accuracy always. Considering the minimal Ron/Reqv can more easily result in a proper crossbar size.