CMOS Analog Integrated Circuits

11.1.8  Algorithmic ADC

Algorithmic or cyclic analog-to-digital converters (ADCs) [31, 32, 33, 34], which are based on the binary division principle, are useful in applications requiring low power consumption and chip area. The core of an algorithmic ADC, as shown in Figure 11.58, consists of a T/H circuit, precision multiply-by-two amplifier, comparator, and summer.

FIGURE 11.58Block diagram of an algorithmic ADC.

Let k be the number of conversion cycles and b_k the bit to be determined. The residue signal, V_x, which is considered the partial remainder of a division, can be expressed as

$V_{x\left(k\right)}\hspace{0.17em}=\hspace{0.17em}\{\begin{array}{l}2V_i,\end{array}$