SLUSD49A September 2017 – January 2019 UCC256303
Refer to the PDF data sheet for device specific package drawings
The output voltage is sensed through the bias winding (BW) voltage sense pin. The sensed output voltage is compared with a fixed threshold to generate output OVP fault. The block diagram of the bias winding voltage sense block is shown below.
The bias winding sense block consists of an inverting op amp to flip the BW signal. The flipped BW signal is then peak detected and sampled at low side turn off edge. The sampled voltage represents the output voltage during this cycle. The S/H output is them compared with OVP comparator. Shown below is the timing diagram of the BW sense block.