ZHCSKD6A October 2019 – April 2024 LM5163
PRODUCTION DATA
The LM5163 integrates an N-channel buck switch and associated floating high-side gate driver. The gate-driver circuit works in conjunction with an external bootstrap capacitor and an internal high-voltage bootstrap diode. A high-quality 2.2-nF, 50-V X7R ceramic capacitor connected between the BST and SW pins provides the voltage to the high-side driver during the buck switch on-time. See the Section 6.3.2 section for limitations. During the off-time, the SW pin is pulled down to approximately 0 V, and the bootstrap capacitor charges from the internal VCC through the internal bootstrap diode. The minimum off-timer, set to 50 ns (typical), ensures a minimum time each cycle to recharge the bootstrap capacitor. When the on-time is less than 300 ns, the minimum off-timer is forced to 250 ns to ensure that the BST capacitor is charged in a single cycle. This is vital during wake up from sleep mode when the BST capacitor is most likely discharged.