A recommended PCB layout for optimal thermal performance would be to have a solid ground plane on the bottom layer, with multiple vias connecting to the thermal pad of the AP1121BSL-13. This helps to dissipate heat efficiently.
To ensure stable output voltage regulation, it's essential to follow the recommended input and output capacitor values, as well as the layout guidelines provided in the datasheet. Additionally, make sure to decouple the input voltage with a suitable capacitor and use a low-ESR output capacitor.
Although the datasheet specifies a maximum input voltage of 18V, it's recommended to limit the input voltage to 15V to ensure reliable operation and prevent damage to the device.
The AP1121BSL-13 is rated for operation up to 125°C, but it's essential to consider the derating curves provided in the datasheet to ensure the device operates within its safe operating area. Additionally, proper thermal design and heat sinking are crucial to prevent overheating.
The output voltage ripple can be calculated using the formula provided in the datasheet: ΔVout = (Iout * ESL) / (Cout * fsw), where ESL is the equivalent series inductance of the output capacitor, Cout is the output capacitance, and fsw is the switching frequency.
AP1121BSL-13 datasheet
by Diodes Incorporated
