Imagine taking a morning jog in a light rain. The combination of weather, your running shoes and nylon attire can generate an electrostatic discharge (ESD), which can abruptly end the life of your smartphone or handheld device upon which you rely.
However, problems associated with over-voltage and over-current still remain an afterthought for most engineers. Why? Circuit protection (CP) is frequently relegated to the end of the engineer's to-do list because design cycle times are compressing as responsibilities are expanding. In today's competitive landscape, engineers fill multiple roles to get the job done–from concept to completion–faster than ever. They have little time to think about the importance of proper circuit protection.
Design functionality suffers when such matters are left to the last minute. As devices get smaller and packed with components, engineers can't find room for CP devices on printed circuit boards (PCB). This results in the need to re-spin boards and losing valuable development time – time that could have been saved, had they thought about CP from the beginning. Even worse, some engineers do think of CP, but they rush choosing a solution and pick the wrong protection device. This often results in functional failures, poor reliability and safety issues.
Here are five CP design recommendations to help engineers save valuable development time:
- Circuit protection as a forethought – The best time to start thinking about CP is after selecting the chip set and before you begin PCB layout. Considering CP too late can have serious repercussions, such as inadequate ESD device space or settling for a non-optimal location, where the device won't function as intended.
- Understand the threats – Everyone understands the simplicity of fuses. Over-voltage is not so obvious. For instance, everyone understands lightning's destructive nature. Did you know it travels across the ground and can create huge glitches in power lines a mile away? This is just one example why understanding the possible threats is so important.
- Define the needs – Designers must imagine how a product will be used in order to accurately predict its CP needs. Once the designer understands the product's target environment and possible threats, they can begin making crucial decisions in selecting the right CP solution.
- Know Thy Standards – Standards impact a product's design, including CP. It's a design engineer's duty to be aware of all relevant standards before starting a project. Knowing and understanding the local/global regulations with which a product must comply has to be part of the early design phase.
- Stay Informed – Tap the web for a wealth of educational resources on the subject. One great example is the Littelfuse Speed2Design website, which is designed to help time-challenged engineers find circuit protection solutions.
