کنفرانس مهندسی برق ایران

صفحه اصلی / سی و چهارمین کنفرانس بین المللی مهندسی برق

Importance of Power Consumption and Resolution of Buffer Located before Converters and New FOM for SAR ADCs

نویسندگان :

Armin Tehranian¹

1- Ferdowsi University of Mashhad

کلمات کلیدی :

Buffer،Converter،SAR ADC،Power Consumption،FOM

چکیده :

This paper discusses the importance of the buffer in successive approximation register analog-to-digital converters (SAR ADCs). Mathematical analyses are performed to demonstrate the significance of proper designing of the buffer which is located before a converter. The effects of the sampling capacitor and frequency and the duty cycle of the sampling clock on the power consumption of the buffer are shown. It is proven that the average power consumption of the converter depends on the sampling frequency but not on the duty cycle of the sampling clock. Moreover, as the sampling time or the duty cycle of the sampling clock increases, the power consumption of the buffer decreases, but the average power consumption of the converter remains unchanged. In this paper, an optimum point in designing of the buffer is considered where not only the resolution of the buffer is more than that of the converter but also the power consumption of the buffer is at its lowest value. Furthermore, it is observed that the effects of the buffer and converter on each other are more apparent in multi-channel systems. Finally, by obtaining the power consumption of the buffer as a dynamic power, a new figure-of-merit (FOM) is presented for converters in which buffer parameters are considered.