Higher order dynamic element matching by shortened tree-structure in Delta-Sigma modulators

A hardware efficient 3-bit second-order dynamic element matching circuit clocked at 300MHz

“…STDEM algorithm is based on conventional TDEM [4], [6]. Fig.1 shows an example of a 9-level TDEM (on the left) and its equivalent STDEM (on the right).…”

“…It seemed to be a good idea but at the price of additional logic. Recently, a hardware efficient ST DEM solution was presented in [6] in which the first layer is completely eliminated, as shown in Fig.1.b. Here, the tree-structure DEM algorithm is well suited if there are no more than 4-DAC cells to control.…”

“…The circumstances of this replacement were analyzed and a mathematical expression for a b-bit STDEM-DAC's analog output Do b (n) is formulated in [6]. It is similar to that of TDEM in [4] as:…”

“…The MDEM benefits of better stability nature of SDEM and hardware efficiency of TDEM. The second one, called ST DEM , is a shortened tree-structured introduced in [6]. It is more stable than the pure TDEM with the same hardware efficiency.…”

Continuous compensation of binary-weighted DAC nonlinearities in bandpass delta-sigma modulators

“…Finally, a bandpass DEM technique which is a modified version of the tree structure [43] was proposed in [44]. The modified tree structure, shown in Fig.…”