NCP4303AMNTWG ON Semiconductor, NCP4303AMNTWG Datasheet - Page 15

• Manufacturer Part Number: NCP4303AMNTWG
• Description: Power Switch ICs - Power Distribution SEC SIDE SYNC RECT DRV
• Manufacturer: ON Semiconductor

Specifications of NCP4303AMNTWG

• Product Category: Power Switch ICs - Power Distribution

parasitic inductance increases with lower R
MOSFETs and/or higher operating frequency.
external compensation inductance (wire strap or PCB). If
the value of this compensation inductance is L
+ L
inductance is exactly the same as the sum of error voltages
created on drain and source parasitic inductances i.e. VL
+ VL
compensation voltage Vl_comp and offsets the current
sense comparator turn−off threshold. The current sense
comparator thus “sees” between its terminals a voltage that
Note that the efficiency impact of the error caused by
Dedicated input (COMP) offers the possibility to use an
source
source
Figure 35. Waveforms from SR System Using MOSFET in TO220 Package without Parasitic Inductance
, the compensation voltage created on this
. The internal analog inverter (Figure 33) inverts
Compensation – SR MOSFET Channel Conduction Time is Reduced
Figure 36. Package Parasitic Inductances Compensation Principle
comp
= L
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DS(on)
drain
drain
15
parasitic inductances effect − refer to Figure 36.
would be seen on the SR MOSFET channel resistance in
case the lead inductances wouldn’t exist. The current sense
comparator of the NCP4303 is thus able to detect the
secondary current zero crossing very precisely. More over,
the secondary current turn−off threshold is then di(t)/t
independent thus the NCP4303 allows to increase operating
frequency of the SR system. One should note that the
parasitic resistance of compensation inductance should be as
low as possible compared to the SR MOSFET channel and
leads resistance otherwise compensation is not efficient.
The NCP4303 offers a way to compensate for MOSFET