HA17384SPS Datasheet, PDF (15/29 Pages) Hitachi Semiconductor – High Speed Current Mode PWM Control IC for Switching Power Supply

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP
A. Control in the case of heavy load
V_CS
I_S
B. Control in the case of light load
V_CS
I_S
As the load becomes heavy and the DC output decreases, the current sensing
level is raised as shown in A. above in order to increase the current in the switching
device in each cycle. When the load decreases, inverse control is carried out as
shown in B. above.
Figure 6 Primary Current Control of Transformer in Current Mode (Conceptual Diagram)
Rev.3.00 Jun 15, 2005 page 15 of 28