Student (m/f/d): Ultra-Low Power LDO for RFID-Tags
During your studies, you can contribute to our ongoing research projects. Join us in pushing the limits of what is technically feasible and be part of breaking new ground together. We offer a variety of challenging and practice-oriented topics for mandatory internships, Bachelor’s or Master’s theses or for student research assistants. You will analyse important scientific preliminary questions and support the project teams with development activities.
Place of work: Erfurt
Team: Microelectronics
Career level:
Thesis
Research field: Integrated sensor systems
Time scope: 6 month
Start: As soon as possible
Application deadline: 2025-12-31
Reference number: IMMS_STUD_ME_0725
In a passive UHF RFID system, energy is harvested from the incoming RF signal. This energy is converted into a DC voltage by a rectifier and then further boosted by a charge-based DC-DC converter. This harvested energy is later used to power the on-chip components, such as EEPROM, as well as external peripherals such as sensors, actuators etc. Due to the stepped nature of the DC-DC converter's charge accumulation, the boosted output voltage exhibits a staircase-like waveform, creating a non-ideal, ripple rich input for the on-chip Low Drop-Out (LDO) regulator. Furthermore, digital circuits frequently switch operating modes, for example entering or existing low-power sleep states, executing bursts of computation, or performing memory access operations. Therefore, the load demand can change rapidly, resulting in large transient variations at the LDO output. This can cause the LDO output to drop below the minimum required levels (undershoot) and rise above the safe margins (overshoot). Such variations can lead to timing violations, bit errors, and malfunctioning digital circuits, which can trigger system instability.
The objective of this thesis is to design an ultra-low power LDO that can effectively regulate a rippled DC input and produce a clean, stable output voltage required for digital and EEPROM operations in the RFID tag. The key challenges include minimizing quiescent current to operate within the tight power budget of the energy-harvesting system, while achieving high power supply ripple rejection (PSRR) and a robust transient response. The design will be implemented and validated using standard 0.18μm CMOS technology.
WHAT TO DO:
* Literature research and understanding of the topic
* Specification and modelling of the LDO
* Circuit design and simulation
* Performance evaluation
* Optional: Layout of complete design
* Documentation
WHAT TO BRING WITH YOU:
* Basic knowledge of analog circuit design
* Strong interest in low voltage and low power circuits
* LDO regulator fundamentals
* Knowledge of the "Cadence Virtuoso" development environment
AND THIS IS US:
We strengthen enterprises with application-oriented research and development in microelectronics, systems engineering and mechatronics and transfer the results of basic research into applications and products. We support companies in launching internationally successful innovations for health, the environment and industry and provide solutions from the feasibility study to series production.
WE ARE LOOKING FORWARD TO MEETING YOU!
We thank you for your interest in working with us.
Please only apply once – for your favourite topic or for the one that comes closest to your interests. This is the quickest way for us to process your application and get back to you. If you are interested in more than one topic, please include this in your cover letter. In case our current suggestions are not suitable, please send us your speculative application with a topic you would like to work on.
WHAT CAN WE OFFER YOU:
* An attractive workplace in a modern, very well-equipped and industry-oriented research institute
* Work directly at the interface between university and industry
* Work in a flexible and creative team and on innovative and challenging topics
For the tasks described in the job offer and with the existing working conditions, an application is possible irrespective of gender and/or any physical disabilities. We foster professional equality of women and men. We invite women in particular to apply. As women are underrepresented at IMMS, they will be given priority in the case of equal suitability, ability and professional performance.
Address:
IMMS Institut für Mikroelektronik- und Mechatronik-Systeme gemeinnützige GmbH (IMMS GmbH)
Ehrenbergstraße 27
98693 Ilmenau
Germany
Contact: Eric Schäfer
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