*2.3. Bandgap Reference (BGR)*

As the target VDD is 1 V, a current-mode bandgap reference (BGR) [9] was selected in this work. Using low-Vt CMOS, the reference voltage VREF is stable at 0.8 V and higher, as shown in Figure 5a. Operation current IDD, including a current generator, is about 200 nA at VDD = 1 V, as shown in Figure 5b. The detector (DET) controls VDD to be 2X VREF with R<sup>0</sup> = R<sup>1</sup> (see Figure 2). Table 1 summarizes the simulated results of the AC-DC converter at corner conditions. ℃ ℃ ℃

**Figure 5.** (**a**) Simulated VREF vs. VDD and (**b**) IDD vs. VDD.


**Table 1.** Simulation result of VDD at corner conditions.
