nPM2100 Inductor Current in Low Power Mode / Ultra-Low Power Mode

[bdub94]

In the nPM2100 datasheet (V1.0):
Figure 24 shows the Switching waveforms in Low Power mode, VOUT = 3.0V, VIN = 1.5V (alkaline AA battery), load = 30mA
Figure 25 shows the Switching waveforms in Ultra-Low Power mode, VOUT = 1.8V, VIN = 1.5V (alkaline AA battery), load = 10mA

The figures show bursts in inductor current to replenish VOUT.
The average inductor current during these burst for both Figure 24 and Figure 25 looks to be ~100mA.

My question is: Why is it 100mA? Is this dependent on the output capacitance? Is there a limit being imposed, and if so, is this limit configurable?

[Kenneth]

Hello,

In LP / ULP, the boost uses the internal fixed peak inductor current (~150 mA) which is not configurable and output capacitance cannot change this peak, but it influence how often the bursts occur or spaced apart.

Kenneth

[bdub94]

Got it. Is the switching frequency during the burst 2MHz?

[Kenneth]

That is correct.

Kenneth