The lowest gain setting is optimized for 50 V_PP with a boost voltage of 30 V. Some applications may not need 50 V_PP, so the user may elect to program the boost converter as low as 15 V to improve efficiency. When using boost voltages lower than 30 V, some special considerations are in order. First, to reduce boost ripple to an acceptable level, a 50 V rated, 0.22 µF boost capacitor is recommended. Second, the full-scale input range may need adjustment to avoid clipping. Normally, a 1.8 V, single-ended PWM signal will give 50 V_PP at the lowest gain. For example, if the boost voltage is set to 25 V for a 40 V_PP full-scale output signal, the full-scale input range drops to 1.44 V for single-ended PWM inputs. An input voltage divider may be desired in this case if a 1.8V I/O is used as a PWM source.