Description:
The Teeter‐Totter effect refers to the phenomenon observed as a regulator’s output impedance changes. When the impedance at the regulator is reduced, the resonant peak at the other end of the trace increases. This effect demonstrates why it’s important to match the impedances of the regulator, planes, and load. The impact of impedance on Clock Jitter is also explored.

Description:
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. Provisions are included for a Bode plot measurement, with the injection resistor, R5, SMA output connectors are also included to simplify connections for many measurements including the 2‐port output impedance measurement we are performing here.

Description:
TDR measures the impedance of the signal path via signal reflections. Discontinuities, added components, or other changes to the signal path can change the capacitance or inductance and hence the impedance of the path. These can be seen using a simple test setup consisting of the Picotest Harmonic comb (portable and produces a fast edge) and the TDR splitter in your kit.