ZHCSLD2E may 2020 – july 2023 UCC28782
PRODUCTION DATA
As VCST drops to VCST(MIN), UCC28782 enters into SBP1 mode and PWMH continues to stay disabled. The purpose of SBP1 is to lower fBUR in order to minimize power loss. SBP1 fixes NSW at two and VCST to VCST(MIN), while the burst off-time is adjusted to regulate the output voltage. As fBUR is well below fLPM, the switching-related loss can be minimized. In addition, lowering fBUR forces both the gate driver and UCC28782 to remain in wait states longer to minimize the static power loss. The equivalent static current of the UCC28782 in SBP can be represented as