ZHCSPF6B february 2022 – may 2023 LMQ66410 , LMQ66420 , LMQ66430
PRODUCTION DATA
The high-side switch driver circuit requires a bias voltage higher than VIN to make sure the HS switch is turned on. The internal 0.1-μF capacitor that is connected between BOOT and SW works as a charge pump to boost voltage on the BOOT terminal to (SW + VCC). The boot diode is integrated on the device die to minimize physical solution size. The CBOOT rail has a UVLO setting. This UVLO has a threshold of VBOOT-UVLO and is typically set at 2.1 V. If the BOOT capacitor is not charged above this voltage with respect to the SW pin, then the part initiates a charging sequence, turning on the low-side switch before attempting to turn on the high-side device.