13. Synchronous Rectification
The Si3406 device has synchronous gate driver (SYNCL) to drive the rectifier MOSFET. At low-load the converter works in discontinu-
ous current mode (DCM); at heavy load, the converter runs in continuous current mode (CCM). At low-load the SWO voltage waveform
has a ringing waveform, which is typical for a DCM operation.
Figure 13.1. SWO and SYNCL Voltage Waveforms at Discontinuous Current Mode (DCM) (Left) and in Continuous Current
Mode (CCM) (Right)
The device operates in non-synchronous mode at light load (I
IN
< 25 mA). As the input current increases, Si3406 automatically changes
its switching operation from "Non-Synchronous" to "Synchronous". The dynamic operation adjustment maximizes overall power efficien-
cy.
UG332: Class 3 Non-Isolated Evaluation Board for the Si3406
Synchronous Rectification
silabs.com
| Building a more connected world.
Rev. 0.1 | 15
