SLUS161F April 1999 – May 2020 UCC2813-0 , UCC2813-1 , UCC2813-2 , UCC2813-3 , UCC2813-4 , UCC2813-5 , UCC3813-0 , UCC3813-1 , UCC3813-2 , UCC3813-3 , UCC3813-4 , UCC3813-5
PRODUCTION DATA.
During the system start-up, VVCC voltage starts to rise from 0 V. Before the VCC voltage reaches its corresponding turn-on threshold, the IC operates in UVLO mode. In this mode, REF pin voltage is not generated. When VVCC is above 1 V and below the turnon threshold, the REF pin is actively pulled low through a 5-kΩ resistor. This way, VREF can be used as a logic signal to indicate UVLO mode.