Ucc2813-0 & ucc28c43d

Ucc2813-0 & ucc28c43d question

ucc28c43 & ucc2813-0 datasheet as the fllowing:
**broken link removed**
**broken link removed**

1.as fgure 1.what does it mean in the figure 1's BLOCK DIAGRAM ?

figure 1
2.as figure 2,the vref pin and Ct/Rt pin connect capacitor and resistor can generate a triangle wave,why ?

figure 2
3.as figure 3,is the opa a comparator?

figure 3

thanks!

https://focus.ti.com/lit/ds/symlink/ucc2813-2.pdf

The upper section indicates the under voltage lock out section. VCC is compared to a voltage by a comparator with hysteresis. It has to rise above a given level before the reference, and the rest of the IC is enabled. When it falls below the lower level the reference and IC is disabled.



In the middle section RT from VREF charges CT to some peak value, 2.45V, at which point circuitry in the block labelled OSC discharges it to some lower level, 50mV.



Next the upper device is a comparator with hysteresis, the lower one is a comparator without hysteresis.

Leading edge blanking disables/blanks the current limit comparator for 100nS when the output drive rises. This is to ignore any initial spikes on the current sense signal during switch turn on.



Genome.