FAN5019B View Datasheet(PDF) - Fairchild Semiconductor

Part Name

Description

Manufacturer

FAN5019B

6-Bit VID Controller 2-4 Phase VR10.X Controller

Fairchild Semiconductor 

FAN5019B

PRODUCT SPECIFICATION

• Whenever a power dissipating component (e.g., a power

MOSFET) is soldered to a PCB, the liberal use of vias,

both directly on the mounting pad and immediately

surrounding it, is recommended. Two important reasons

for this are: improved current rating through the vias, and

improved thermal performance from vias extended to the

opposite side of the PCB where a plane can more readily

transfer the heat to the air. To achieve the best thermal

dissipation to the air around the board, make a mirror

image of any pad being used to heatsink the MOSFETs on

the opposite side of the PCB . To further improve thermal

performance, use the largest possible pad area.

• Route the output power path to encompass a short

distance. The output power path is formed by the current

path through the inductor, the output capacitors, and the

load.

• For best EMI containment, use a solid power ground

plane as one of the inner layers extending fully under all

the power components.

Signal Circuitry

• The output voltage is sensed and regulated between the

FB pin and the FBRTN pin (which connects to the signal

ground at the load). To avoid differential mode noise

pickup in the sensed signal, the loop area should be small.

Thus the FB and FBRTN traces should be routed adjacent

to each other atop the power ground plane back to the

controller.

• Connect the feedback traces from the switch nodes as

close as possible to the inductor. Connect the CSREF

signal to the output voltage at the nearest inductor to the

controller.

28

REV. 1.0.0 Jul/15/05

Share Link: