A good PCB layout for the LMP8640 involves keeping the input and output capacitors close to the device, using a solid ground plane, and minimizing trace lengths and widths to reduce parasitic inductance and capacitance.
To ensure stability, it's essential to follow the recommended component values and PCB layout guidelines, and to add a compensation capacitor (CC) between the COMP and FB pins. Additionally, ensure that the output capacitor has a low equivalent series resistance (ESR) and is placed close to the device.
The LMP8640 can handle input voltages up to 42V, but it's recommended to operate within the specified input voltage range (4.5V to 36V) for optimal performance and reliability.
Choose an output capacitor with a low ESR, high ripple current rating, and a voltage rating that exceeds the output voltage. A ceramic or polymer capacitor with an X5R or X7R dielectric is recommended. The output capacitor value should be between 10uF to 22uF, depending on the output voltage and desired ripple performance.
The LMP8640 has a thermal derating curve that reduces the maximum output current as the junction temperature increases. Refer to the datasheet for the specific derating curve, and ensure that the device is operated within the recommended temperature range (–40°C to 125°C) for optimal performance and reliability.
LMP8640HVMKX-H/NOPB datasheet
by Texas Instruments
