When hardware system designers design product applications, they need to carefully choose the right analog signal path IC. Whether design consumer electronics MP3 player, or medical ultrasound equipment, to ensure that they are able to maintain efficient operation, engineers have to make the right balance. --Like the noise ratio (SNR), resolution, the total harmonic distortion (THD), input offset voltage, jitter and supply current indicators such as assessment and decision priority, in order to elect the right analog signal path IC. Choose the right path signal IC, users will be able to bring the best visual and sound experience. But another element must not be overlooked considering that the signal path for each IC needs to "clean" power. Power management is usually the final part of system design. (Figure 1) shows how the power supply for the signal path examples.

                Figure 1: power supply design will affect the signal path IC performance.

Power impact on performance signal path
Not surprising that the power it will certainly affect the integrity of analog signals, but will eventually affect the overall system performance. To enhance signal path of one of the easiest way is to find the right way power supply. In the choice of power supply, will affect the analog signal path of one of the key parameters, is the power-line noise or ripple (ripple). Power supply ripple or the noise will Operational amplifier coupled to the output, increased lock-loop (PLL) or voltage control oscillator (VCO) jitter, or the lower ADC SNR. Therefore only low noise and low ripple power, the signal path in order to improve performance.

Power line noise or ripple with a variety of possible sources. If the PCB production lines and cable poorly designed, the system's high-speed data and high-frequency signals in itself will generate noise, such as antenna will have the effect of launch. The digital IC, such as micro-controllers, field programmable gate arrays (FPGA) and complex programmable logic components (CPLD), have quickly jumped on the verge of variable rate (edge rates), triggered changes in current , Lead to the creation of electromagnetic interference radiation into the system. And silicon system IC chip will appear in the internal thermal noise, because the temperature is higher than the absolute temperature scale Casparian 0 degrees, elements of the random movement and produced by the collision.

There are three common ways can be in the path of the signal noise and ripple to a minimum: PCB set up carefully designed system, the appropriate power supply bypass treatment and the correct choice of power. Although the PCB design still depends on the specific system, in normal circumstances, PCB settings, including the right to be considered components of the layout so that the signal path connecting the line and the introduction of the minimum length of the grounding (solid ground), and so on.