SLVSGT5 December 2023 TPS55289-Q1
PRODUCTION DATA
Each of the two high-side MOSFET drivers is biased from its floating bootstrap capacitor, which is normally re-charged by VCC through both the external and internal bootstrap diodes when the low-side MOSFET is turned on. When the TPS55289-Q1 operates exclusively in the buck or boost regions, one of the high-side MOSFETs is constantly on. An internal charge path, from VOUT and BOOT2 to BOOT1 or from VIN and BOOT1 to BOOT2, charges the bootstrap capacitor to VCC so that the high-side MOSFET remains on.