JAJSDZ5 October 2017 LM2623-Q1
PRODUCTION DATA.
Figure 12 follows proper layout guidelines — use as a guide for laying out the LM2623-Q1 circuit. The LM2623-Q1 inductive boost converter sees a high switched voltage at the SW pin and a step current through the Schottky diode and output capacitor each switching cycle. The high switching voltage can create interference into nearby nodes due to electric field coupling (I = C × dV/dt). The large step current through the diode and the output capacitor can cause a large voltage spike at the SW and BOOST pins due to parasitic inductance in the step current conducting path (V = L × di/dt). Board layout guidelines are geared towards minimizing this electric field coupling and conducted noise.
Boost Output Capacitor Placement, Schottky Diode Placement, and Boost Input / VDD Capacitor Placement detail the main (layout sensitive) areas of the LM2623-Q1 inductive boost converter in order of decreasing importance: