Minimum input voltage of DC-DC converter on EFM32 Series 1 devices

by <a href="http://community.silabs.com/t5/Welcome-and-Announcements/Community-Ranking-System-and-Recognition-Program/m-p/140490#U140490"><font color="#000000"><font size="2">Hero Employee</font></font> </a> amenleung on ‎03-01-2017 06:01 PM

Question

What is the minimum input voltage of the DC-DC converter on EFM32 Series 1 devices?

Answer

The minimum input voltage of the DC-DC converter on EFM32 Series 1 devices is 2.4 V.

 

As the DC-DC input supply voltage nears its minimum voltage, the DC-DC converter performance is impacted in two ways:

  1. The DC-DC converter efficiency decreases to a point where it provides limited benefit compared to Bypass mode.
  2. The DC-DC converter eventually loses the ability to maintain a constant output voltage and enters dropout. When dropout occurs, the DC-DC will no longer be in regulation, and significant overshoot/undershoot will occur, which may cause the brown-out detectors to trip and reset the device.

To avoid dropout, the system should switch the DC-DC to Bypass mode when the input supply drops to the minimum.