Datasheet

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Layout Guidelines
Cut out in
ground plane
Signal
GND
Power
GND
GND
ICOMP
ISENSE
VINS VCOMP
VSENSE
VCC
GATE
UCC28019
SLUS755B – APRIL 2007 – REVISED DECEMBER 2007
As with all PWM controllers, the effectiveness of the filter capacitors on the signal pins depends upon the
integrity of the ground return. The pinout of the UCC28019 is ideally suited for separating the high di/dt induced
noise on the power ground from the low current quiet signal ground required for adequate noise immunity. A star
point ground connection at the GND pin of the device can be achieved with a simple cut out in the ground plane
of the printed circuit board. As shown in Figure 27 , the capacitors on ISENSE, VINS, VCOMP, and VSENSE
(C11, C12, C15, C17, and C16, respectively) must all be returned directly to the quiet portion of the ground
plane, indicated by Signal GND, and not the high current return path of the converter, shown as the Power GND.
Because the example circuit in Figure 27 uses surface mount components, the ICOMP capacitor, C10, has its
own dedicated return to the GND pin.
Figure 27. Recommended Layout for the UCC28019
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Product Folder Link(s): UCC28019