STMicroelectronics provides a recommended PCB layout in the application note AN4171, which includes guidelines for thermal pad connection, copper pour, and via placement to ensure optimal thermal performance.
The input capacitor selection depends on the input voltage, output voltage, and output current. A general guideline is to choose a capacitor with a voltage rating of at least 1.5 times the input voltage, and a capacitance value between 10uF to 22uF. Refer to the application note AN4171 for more detailed guidance.
The maximum allowed voltage on the EN (enable) pin is 6V. Exceeding this voltage may damage the device. It's recommended to use a voltage divider or a buffer circuit to ensure the EN pin voltage remains within the specified range.
The STM6904SFEDS6F is rated for operation up to 150°C (junction temperature). However, the device's performance and reliability may degrade at high temperatures. It's essential to follow the recommended thermal design guidelines and consider derating the device's performance at elevated temperatures.
Start by verifying the input voltage, output voltage, and output current. Check the PCB layout for any thermal or electrical issues. Use an oscilloscope to monitor the switching node and output voltage. Consult the datasheet and application notes for troubleshooting guidelines and common pitfalls to avoid.
STM6904SFEDS6F datasheet
by STMicroelectronics
