## 3 Results  
The proposed CDBA structure and filter application were designed using the Cadence Virtuoso environment, utilizing 0.18 \(\upmu\)m CMOS technology from TSMC. The CDBA is capable of operating with a supply voltage of 0.3 V while consuming only 170 nW of power for biasing current \(I_{B}\) = 10 nA. The transistor dimensions in \(\upmu\)m/\(\upmu\)m are shown in Table 1.  
Figure 5 shows the DC current characteristics of the CDBA (a) \(I_{z}\) versus \(I_{p}\) (with \(I_{n}\) = 0) and (b) \(I_{z}\) versus \(I_{n}\) (with \(I_{p}\) = 0) with a grounded \(z\)-terminal. As shown, the current operating range extends up to \(\pm\)100 nA. With the \(w\)-terminal loaded with a \(C_{L}\) = 5 pF capacitance, the DC voltage characteristic \(V_{w}\) versus \(V_{z}\) is shown in Figure 6. The circuit offers a wide operating range of up to \(\pm\)120 mV. \begin{table}
\begin{tabular}{c c} \hline \hline
**Component** & **W/L (\(\upmu\)m/\(\upmu\)m)** \\ \hline M\({}_{1}\), M\({}_{2}\), M\({}_{\text{B}}\), M\({}_{\text{1}c}\), M\({}_{\text{2}c}\), M\({}_{\text{1b}}\), M\({}_{\text{2b}}\) & 50/1 \\ \hline M\({}_{3}\), M\({}_{4}\), M\({}_{\text{3}c}\), M\({}_{\text{4}c}\), M\({}_{\text{3b}}\) & 5\(\times\) 50/1 \\ \hline M\({}_{5}\), M\({}_{6}\), M\({}_{\text{Sc}}\), M\({}_{\text{6}c}\), M\({}_{\text{5b}}\), M\({}_{\text{6b}}\) & 100/1 \\ \hline M\({}_{7}\), M\({}_{\text{8}}\), M\({}_{\text{7}c}\), M\({}_{\text{8}c}\), M\({}_{\text{7b}}\) & 5\(\times\) 100/1 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The transistor dimensions of the proposed CDBA. Figure 4: Proposed current-mode third-order low-pass filter using CDBAs. Figure 7 shows the frequency magnitude characteristics of the CDBA--\(V_{w}/V_{z}\) (with \(C_{L}\) = 5 pF), \(I_{z}/I_{p}\) (with \(I_{n}\) = 0), and \(I_{z}/I_{n}\) (with \(I_{p}\) = 0). The voltage gain \(V_{w}/V_{z}\) at low frequencies was 0.996 at the \(-3\) dB bandwidth of 35 kHz. For the current gains, \(I_{z}/I_{p}\) and \(I_{z}/I_{n}\), the values were 0.998 and 0.997, with bandwidths of 79.4 kHz and 100 kHz, respectively. The performance data of the proposed CDBA are shown in Table 2. The current and voltage offsets represent the standard deviation values obtained from a Monte Carlo analysis (including process and mismatch variations) with 200 simulation runs. Table 3 provides a comparative analysis of the proposed CDBA against previously reported designs, including earlier works [12; 29; 31] and recent publications [49]. This comparison demonstrates the proposed CDBA's superior performance in terms of lower supply voltage and significantly reduced power consumption. Notably, a comprehensive literature survey confirms that no existing CDBA achieves sub-volt operation with nanowatt-range power consumption. Consequently, the proposed CDBA is ideally suited for low-voltage, low-power current-mode signal processing, particularly in biomedical applications. For the proposed filter, the component values of the LC ladder low-pass filter in Figure 3a are given by the following: \(R_{s}=R_{L}\) = 440 k\(\Omega\), \(C_{1}\) = \(C_{3}\) = 3 nF, and \(L_{1}\) = 1.161 kHz. The component values of the proposed low-pass filter in Figure 4 are as follows: \(R\) = 440 k\(\Omega\), \(R_{s}\) = \(R_{L}\) = 520 k\(\Omega\), \(C_{1}\) = \(C_{3}\) = 3 nF, and \(C_{L1}\) = 6 nF. Figure 8 shows the frequency magnitude and phase characteristics of the low-pass filter (LPF). The magnitude at 1 Hz and the \(-3\) dB cut-off frequency for the RLC and LPF were \(-6.02\) dB and \(-6.21\) dB, and 105 Hz and 110 Hz, respectively. The tuning capability of the filter is demonstrated by adjusting the \(C=C_{1}=C_{3}\)= 2\(C_{L1}\) for values of \(C\) = 1.5, 3, and 6 nF. The corresponding cut-off frequency was 55 Hz, 110 Hz, and 229 Hz, as shown in Figure 9.  
Figure 6: DC voltage characteristic: \(V_{w}\) versus \(V_{z}\). Figure 7: Frequency magnitude characteristics: \(V_{w}/V_{z}\), \(I_{z}/I_{p}\), and \(I_{z}/I_{n}\).