Ultra-Low Voltage Ultra low voltage is a concept that has seen processors use less power while at the same time increasing their performance. Most digital circuits in the world today are being designed in such a manner that they can be more energy efficient and thus minimize power consumption. Aggressive voltage supply is one of the mechanisms adopted to make the digital circuits more energy efficient. The new strategies that are being adopted by many manufacturers of digital circuits are meant to ensure that the circuits consume less power. The digital circuits are also modified in order to reduce complications to the threshold designs thereby helping reduce extreme sensitivity of the devices which negatively affects their performance. For example, most mobile devices today are powered by the rechargeable battery. In order to ensure that these batteries are effective in improving the performance of the mobile devices, the circuit designs in these batteries are being designed to ensure that they supply more power to the devices. Today, the Cellular phones have paved way for innovation of energy efficient batteries that have yielded huge profits for the manufacturers (Hanson, et al., 2006). The ultra-low mechanism is the one that has been adopted in batteries to make them more energy efficient. Further research is being conducted on the ultra-low voltage circuits in order to ensure that future batteries become cheaper and supply more power to the devices. These batteries will be helpful especially now that high performing computer processors which demand more power are being designed. For example, the sub-threshold sensor processors are being incorporated in many devices in order to improve their performance. These processors demand more power thereby leading to concentrations on the development of ultra-low voltage circuits that can supply enough energy to power the devices (Hanson, et al., 2006). The implementation of voltage scaling in ultra-low voltage circuits has proved to be an effective solution to the high demand for power by today’s sophisticated microprocessors. To avoid reducing the performance of devices when voltage is reduced, the devices are being designed in a manner that supports quadratic reduction of energy consumption. This ensures that the devices continue to operate optimally while consuming less power (IEEE Computer Society, 2004). Digital Logic Design Digital logic design a system adopted in computer and electrical engineering which makes use of simple number values in order to produce input and output operations. Digital logic designs are mostly used in various things such as Cell phones and computers. For example, sub-threshold sensor processors are designed using the concept of digital logic designs. They are efficient in terms of energy consumption. The devices that use these processors therefore require less energy to power them up. The designing of these processors involves a two-stage multi-architecture process whose aim is to moderate the effect that the sub-threshold activity would bring to the processors. The process is carried out by ensuring that the operating frequency of the devices is kept constant thereby increasing their productivity significantly (Zhai, et al., n.d). Dynamic voltage scaling is a new me