Texas Instruments provides a recommended PCB layout in the datasheet, but it's also recommended to follow general guidelines for thermal management, such as using a solid ground plane, placing thermal vias under the device, and keeping the thermal path short and direct.
To ensure accurate and stable output voltage, it's essential to follow the recommended input and output capacitor values, as well as the recommended layout and placement guidelines. Additionally, the output voltage can be trimmed using the VTRIM pin, and the device also has a built-in soft-start feature to prevent output voltage overshoot during startup.
While the datasheet specifies a maximum input voltage of 42V, it's essential to consider the maximum voltage rating of the input capacitor and other components in the circuit. It's recommended to derate the input voltage to ensure reliable operation and prevent damage to the device or other components.
The LM21305SQX/NOPB has built-in overcurrent protection (OCP) and thermal shutdown (TSD) features. However, it's still essential to add external protection components, such as fuses or PTC resistors, to prevent damage from excessive current or temperature. Additionally, the device's thermal pad should be connected to a solid ground plane to ensure effective heat dissipation.
The LM21305SQX/NOPB is rated for operation up to 125°C, but it's essential to consider the device's power dissipation and thermal management when operating in high-temperature environments. The device's junction temperature (TJ) should be kept below the maximum rating, and the thermal pad should be connected to a solid ground plane to ensure effective heat dissipation.
LM21305SQX/NOPB datasheet
by Texas Instruments
