Texas Instruments provides a recommended PCB layout in the application note SLUA623, which includes guidelines for component placement, trace routing, and thermal management to ensure optimal performance and minimize electromagnetic interference (EMI).
The input capacitor selection depends on the input voltage, output voltage, and switching frequency. A general guideline is to choose a capacitor with a voltage rating of at least 1.5 times the maximum input voltage, and a capacitance value of 10-22 μF. Additionally, consider the capacitor's equivalent series resistance (ESR) and ensure it is compatible with the device's input impedance.
The maximum allowable voltage drop across the internal FETs is not explicitly stated in the datasheet. However, as a general guideline, it is recommended to keep the voltage drop below 1 V to ensure reliable operation and minimize power losses. Excessive voltage drop can lead to increased power dissipation, reduced efficiency, and potentially cause the device to overheat.
The UCC27423DG4 is rated for operation up to 150°C junction temperature. However, the device's performance and reliability may degrade at high temperatures. It is essential to ensure proper thermal management, such as heat sinking and airflow, to keep the junction temperature within the recommended range. Additionally, consider derating the device's performance and power handling capabilities at high temperatures.
To troubleshoot issues with the UCC27423DG4, start by verifying the PCB layout and component selection against the recommended guidelines. Check for proper decoupling, filtering, and termination of the input and output signals. Use an oscilloscope to monitor the device's input and output waveforms, and look for signs of oscillation or instability. Consult the application notes and technical documentation provided by Texas Instruments for guidance on troubleshooting and debugging techniques.
UCC27423DG4 datasheet
by Texas Instruments
