JAJSUQ8C June 2024 – September 2024 TPSM81033
ADVANCE INFORMATION
As for all switching power supplies, especially those running at high switching frequency and high currents, layout is an important design step. If the layout is not carefully done, the regulator suffers from instability and noise problems. To maximize efficiency, switch rise and fall time are very fast. To prevent radiation of high frequency noise (for example, EMI), proper layout of the high-frequency switching path is essential. The input capacitor needs not only to be close to the VIN pin, but also to the GND pin in order to reduce input supply ripple.
The most critical current path for all boost converters is from the switching FET, through the rectifier FET, then the output capacitors, and back to ground of the switching FET. This high current path contains nanosecond rise and fall time and must be kept as short as possible. Therefore, the output capacitor not only must be close to the VOUT pin, but also to the GND pin to reduce the overshoot at the VOUT pin.
For better thermal performance, TI suggest to make copper polygon connected with each pin bigger.