Switched mode Battery Charger CC/CV operation

Hi,

Shown below is the internal block diagram of a switched mode battery charger IC (LT1510). The LT1510 is a current mode, PWM (pulse-width modulated), positive buck switcher that operates in one of two states: constant current or constant voltage.

I am having difficulty understanding the operation and internal block diagram of IC (especially the highlighted sections). I have only beginner level knowledge on current mode control and op-amp compensation.

  1. Can somebody explain how 'constant voltage- constant current' mode happens here?
  2. The current mode control employed is peak current mode control. In peak current mode control inductor current is sensed ( along with slope compensation) and compared with a control voltage derived from the voltage control loop. What is the purpose of current amplifiers CA1 and CA2 here?

Thanks

Divya K S