The circuit is an integrated point of load synchronous buck regulator with a 5V input and a 1.2V/2.5A output. The device uses emulated current mode control, making it simple to create a flat impedance output. Easily accessible 0805 chip size components make it easy to customize or experiment with different component values. This is a fully self-contained demo board using USB input power and an on-board resistive load.
Demonstration Circuits
The LM20143B VRM demo board is designed for Bode plot measurement, with the injection resistor, R5, included as well as test-points for the injection signal and measurement (TP3 and TP4). SMA output connectors are also included to simplify connections for many measurements including the 2-port output impedance measurement, step load and other common measurements.
The board is USB powered by connecting a USB cable with a type B connector to the power connector USB1. (CAUTION: R9 and R10 GET HOT - DO NOT TOUCH)