SLVSGG8B November 2023 – August 2024 TPS6287B10 , TPS6287B15 , TPS6287B20 , TPS6287B25
PRODMIX
Figure 8-15 shows a functional block diagram of the power-good function in a secondary device. During initialization, the device presets FF2, which pulls down the PG pin and forces the devices in a stack to operate in DCM. When the device completes the internal start-up sequence, it resets FF2, which turns off Q1. In a stacked configuration all devices share the same PG signal, and therefore the PG pin stays low until all devices in the stack have completed the start-up. When that happens, FF1 is set and the converters operate in CCM. FF1 and FF2 are pre-set such that DCM is allowed each time the converter is disabled, either by the EN pin, EN bit, thermal shutdown or UVLO.