This section covers what is meter tampering, why is this a problem for utility providers, and some common ways a meter is tampered.
Understand the performance and tradeoffs of the traditional low noise and high efficiency approach of using a DC/DC followed by an LDO. Visualize other systems that could use the same approach, with the appropriate DC/DCs and LDOs in different packages and with different features.
Understand the performance and trade-offs of the traditional low noise and high efficiency approach of using a DC/DC followed by an LDO, through a deep dive into TIDA-01566. The size, quiescent current, efficiency, temperature rise, noise, and adaptability of three different approaches are compared: DC/DC + LDO, DC/DC only, and LDO only.
What you will learn in this webinar:
- How to achieve a low noise at a negative output voltage with the inverting buck topology
- Understanding how the buck output stage and filtered reference voltage attenuate noise
- The elimination of LDOs when powering data converters by utilizing these low-noise features
The first line of defense against tampering by bypassing current, reversing connections, and disconnecting leads is the meter case. Due to this, it is common for utilities to require some form of intrusion detection system to detect when someone opens a case. In this section, we will cover how to detect someone trying to open the case of a meter.
For anti-tampering, it is common to try to detect the presence of a strong magnet. In this section, we will cover the use of hall sensors for low-power detection of strong magnetic fields in three dimensions. Details on our magnetic tamper detection reference design, TIDA-00839, will be provided as well as some of the design considerations that were kept in mind when creating this reference design.
In this section, we will cover how to harden a meter against these magnetic tamper attacks by using shunts for current sensors. For poly-phase implementations, I will go over how to use isolated delta sigma modulators to add the necessary isolation to use shunt current sensors and create magnetically immune poly-phase energy measurement systems. The TIDA-00601 and TIDA-01094 reference designs, which show how to implement a poly-phase isolated shunt measurement system, will be discussed as well as the associated AMC1304 high-side power supplies used in these designs.
In this section, a summary of the entire “Anti-tamper Techniques to Thwart Attacks on Smart Meters” training module would be covered. This summary would cover the “Detecting case tamper attacks using inductive switches “, “Detecting magnetic tampering using hall-effect sensors “, and “Hardening a meter against magnetic tamper attacks “ sections of the training series. Links will be provided for the reference designs and design tools that were discussed during this training series.
These training videos will be used to better understand LDOs, and include information on designing the best ADC power supply, stabilizing an LDO, measuring LDO noise and power supply rejection ratio, measuring thermal resistance between junction temperature and ambiance, and more.
For noise-critical portable applications, such as GPS receivers, connectivity, and sensing, power supply designers always had to choose between longer battery run time (from higher efficiency) or higher signal chain performance (from the increased sensor sensitivity possible with a quieter power supply). For line-powered industrial or communications equipment applications, designers have been forced to dissipate significant amounts of power in LDOs to achieve the desired noise performance. Achieving both low noise and high efficiency was impossible.
Deep Dive into the Light Load Efficient, Low Noise Power Supply Reference Design for Wearables and IoT (TIDA-01566)