Flexibility is key in a low-power application design. One such example is changing the output voltage value. The traditional way is to use an adjustable external feedback divider, but this will cause not just higher inaccuracy but also higher I_Q. Modern nanoampere power converters use R2D interfaces (Figure 21), which enable the digitized setting of output voltages without consuming extra current, since the function will shut down after booting the device.

Figure 21 R2D interface.