The buffer capacitor stores the required energy for the high current LED pulses and is placed at the input of the LED driver. The capacitor is discharged during the on-state of the IR LEDs and recharged during the off-state of the IR LEDs. The buffer capacitor is required to store enough energy to drive the LEDs for the specified pulse duration and power.

To calculate the minimum required capacitor size, follow the steps in the Design Steps section.

Once the minimum capacitor size has been calculated, a fitting capacitor can be selected and checked if the required PCB dimensions can be fulfilled as the capacitor size has a significant impact on the overall solution size.