Creating Reliable IoT Products Through Circuit Protection Design Techniques
The Internet of Things (IoT) connects a lot of dissimilar devices that collaborate together with the intent of gathering and sharing data. Threats to this ecosystem, such as risks of system failure from various overcurrent, overtemperature, electrostatic (ESD) and electromagnetic pulse (EMP) apart from environmental conditions are very likely and mitigation methods are thus absolutely necessary to ensure a high level of reliability that is expected from the IoT infrastructure. Product designers worry about device functionality and performance primarily but as more devices get included into the IoT infrastructure, it is essential to include circuit protection techniques in to the product design cycle. Penguin Edge has been creating connected embedded computing solutions and platforms covering a wide range of IoT applications. These solutions come in extremely compact hardware with multi-layered HDI PCB designs for high speed digital and mixed signal systems. To maintain the high-level of reliability expected from these IoT systems, circuit protection is critical as a crucial design goal. A few key protection techniques are elaborated below:
- ESD Diodes/Arrays provide I/O port protection from transients caused by Electrostatic Discharge (ESD), Electrical Fast Transients (EFT) and other induced voltages.
- EMI suppression filters reduce the high frequency electromagnetic noise transmitted through conduction that may cause interference with other devices.
- Temperature sensors/ Thermal diodes/Thermistors help to monitor the system and chip temperature. This enables the system software to trigger a fault indication interrupt if a predetermined threshold value is exceeded. Coupled with Qualcomm’s inbuilt thermal management algorithm that runs on its processor, thermal management on the system is guaranteed to be fool proof.
- Hot swap controllers help in safe removal and insertion of a module from a live backplane/server and also offers continuous protection from short circuits and overcurrent faults.
- Programmable Voltage monitoring circuits help to monitor the desired voltage levels at specific locations on the system. This enables the system software to trigger a shutdown/power cycle/reset as necessary if the monitored values exceed the predetermined thresholds.
- Low resistance Fuses (Over current protection) provide overcurrent protection of an electrical circuit.
- Transients within a circuit can rise rapidly which lead to voltage spikes and these must be prevented from appearing across delicate electronic circuits and components. Varistors/Thyristors (Over voltage protection) protect the circuit from a sudden voltage spike that exceeds the predetermined limit.
- Bleeder resistors are used as necessary to discharge the electric charge stored in the power supply's filter capacitors when the equipment is turned OFF, for safety reasons.
- Current limiting circuits limits the current from the regulated power supply to a maximum amount determined by the circuit. These circuits are necessary to provide protection in cases of a short circuit or other unintended overload conditions.
- Leakage current protection circuits limit/stop unwanted transfer of energy from one circuit to another.