The TLV61046A implements a power save mode with pulse frequency modulation (PFM) to improve efficiency at light load. When the load current decreases, the inductor peak current set by the output of the error amplifier declines to regulate the output voltage. When the inductor peak current hits the low limit of 200 mA, the output voltage will exceed the setting voltage as the load current decreases further. When the FB voltage hits the PFM reference voltage, the TLV61046A goes into power save mode. In power save mode, when the FB voltage rises and hits the PFM reference voltage, the device continues switching for several cycles because of the delay time of the internal comparator, then it stops switching. The load is supplied by the output capacitor and the output voltage declines. When the FB voltage falls below the PFM reference voltage, after the delay time of the comparator, the device starts switching again to ramp up the output voltage.

Figure 7-1 Output Voltage in PWM Mode and PFM Mode