The driver of the High-Side (HS) switch requires bias higher than V_IN. The capacitor, CBOOT, connected between CBOOT and SW, works as a charge pump to boost voltage on the CBOOT pin to SW + VCC. A boot diode is integrated on the LM61440 die to minimize external component count. It is recommended that a 100-nF capacitor rated for 10 V or higher is used. The V_{BOOT_UVLO} threshold (2.1 V typ.) is designed to maintain proper HS switch operation. If the CBOOT capacitor voltage drops below V_{BOOT_UVLO}, then the device initiates a charging sequence, turning on the low-side switch before attempting to turn on the HS switch.