UCC28070-Q1
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SLUSA71A –JULY 2010–REVISED JUNE 2011
Current Sense Offset and PWM Ramp for Improved Noise Immunity
To improve noise immunity at extremely light loads, a PWM ramp with a dc offset is recommended to be added
to the current sense signals. Electrical components RTA, RTB, ROA, ROB, CTA, CTB, DPA1, DPA2, DPB1, DPB1 CTA
,
CTB form a PWM ramp that is activated and deactivated by the gate drive outputs of the UCC28070. Resistor
ROA and ROB add a dc offset to the CS resistors (RSA and RSB).
VCC
DPA1
ROA
DPA2
RTA
CSA
GDA
CTA
RSA
VCC
DPB1
ROB
DPB2
RTB
GDB
CTB
RSB
Figure 26. PWM Ramp and Offset Circuit
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