The three largest FPGA manufacturers – Actel, Altera and Xilinx – have released power-saving FPGA designs, including new versions of established products. Features typically include static, idle and special modes and power analysis software so engineers can accurately calculate power consumption at each stage of product design. Improved place-and-route and custom layout tools also help reduce power consumption during “back end” PCB design tasks.
Today, there is an abundant range of FPGA designs on the market, so how do you go about choosing one that is right for your needs? Performance,cost and capacity all count, but to this you can add the power profile of the system you are designing. Industrial, medical,military or consumer buyers; whatever your target market, you will find the demand for portable electronic hardware is becoming increasingly orientated towards energy-efficient products.
There are two types of FPGA: non-volatile and volatile. Non-volatile types are used in products which would traditionally use a CPLD or other low capacity integrated circuit; they retain their RAM memory when powered down and do not need a continuous power supply. Volatile FPGAs are more flexible,but require a constant power source to retain stored data.
Many PCB design engineers do not realize that volatile FPGAs have two extra power-control components, one for configuration (power consumed when the FPGA is programmed during system power-up), and a Power-On inrush component, employed during functional power-ups. They also have an external PROM to store configuration data. Even where flash memory is installed, it still adds to power consumption.
PCB designers working on volatile FPGA installations must be aware of the difference between the two types,and ensure the power supply and batteries chosen match the configuration and inrush power of the chip.These components can negatively impact on the system design,especially where multiple FPGAs are used with a common power supply,or share a board.The problem is exacerbated in systems which have frequent On-Off cycles,which can shorten battery life considerably.However,a growing number of FPGAs are low-power and non-volatile in design.We at Enventure Technologies have been specializing in FPGA design for over 10 years,producing energy-efficient,reliable,customized systems for clients world-wide.