Datasheet

UC28023
UC28025
SLUS557F -- MARCH 2003 -- REVISED AUGUST 2010
14
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The circuit for the UC28025 shown in Figure 15 describes achievement a constant volt-second product clamp
over varying input voltages. The ramp generator components, R
T
and C
R
are chosen so that the ramp at Pin
9 (ILIM/SD) crosses the 1-V threshold at the same time the desired maximum volt-second product is reached.
The delay through the functional inverter block must be such that the ramp capacitor can be completely
discharged during the minimum deadtime.
UDG--03050
14
9
OUTB
ILIM/SD
UC28025
11
CR
RT
OUTA
VIN
Figure 15. Achieving Constant Volt-Second Product Clamp with the UC28025