SaberRD Design Example: Synchronous Buck Converter using UCC3882

Datsen Davies Tharakan

Introduction:
Synchronous Buck converter topology has advantage of improved efficiency over nonsynchronous buck converter due to lower voltage drop at low-side MOSFET when compared to power diode of nonsynchronous buck converter. Synchronous buck converter has made its presence in high efficiency applications like battery charger for Laptops, Voltage Regulator Modules (VRM) in motherboards of PCs and laptops, power audio amplifier, quadcopter, brushed and brushless motor controllers.
This design example illustrates the operation of synchronous buck converter in Pentium 2 processor where the DC-DC converter is controlled by current mode synchronous controller UCC3882.The design example is available with test benches created using Experiment Analyzer in SaberRD that helps to automate analysis, post processing measurements and pass/fail test conditions to check whether design specifications are met or not. Initially, when design specifications are tested, it is found that High side MOSFET is dissipating more power and converter efficiency is less than 90%. The design example explains the investigation carried out and steps to improve efficiency. Later, more analysis like Six Sigma quality check on output voltage and operation during Under Voltage Lock Out (UVLO) are carried out using Experiment Analyzer.

How to use the example:
Download the attached "sync_buck_converter.zip" and unzip to a local folder. Open the sync_buck_conv.ai_dsn in SaberRD and run the experiments listed in the Experiment Analyzer.

For more details of the design, how to run the design, etc., refer to the README.pdf file in the attachments.

Note:
This design example works only in SaberRD commercial edition 2017.06 and above.

Circuit Diagram: