ACT4524
Rev 1.1, 22-Feb-16
APPLICATIONS INFORMATION
2) The high power loss components, e.g. the
controller, Schottky diode, and the inductor
should be placed carefully to make the thermal
spread evenly on the board.
Current Sense Resistor
The traces leading to and from the sense resistor
can be significant error sources. With small value
sense resistors, trace resistance shared with the
load can cause significant errors. It is
recommended to connect the sense resistor pads
directly to the CSP and CSN pins using “Kelvin” or
“4-wire” connection techniques as shown below.
3) Place input decoupling ceramic capacitor CIN as
close to VIN pin as possible. CIN should be
connected to power GND with several vias or
short and wide copper trace.
4) Shottky anode pad and IC exposed pad should
be placed close to ground clips in CLA
applications.
PCB Load
Trace
5) Use “Kelvin” or “4-wire” connection techniques
from the sense resistor pads directly to the CSP
and CSN1, CSN2 pins. The CSP ,CSN1, and
CSN2 traces should be in parallel to avoid
interference.
Kevin Sense
Traces
Sense
Resistor
6) Place multiple vias between top and bottom
GND planes for best heat dissipation and noise
immunity.
PCB Layout Guidance
When laying out the printed circuit board, the
following checklist should be used to ensure proper
operation of the IC.
7) Use short traces connecting HSB-CHSB-SW
loop.
8) SW pad is noise node switching from VIN to
GND. It should be isolated away from the rest
of circuit for good EMI and low noise operation.
1) Arrange the power components to reduce the
AC loop size consisting of CIN, VIN pin, SW pin
and the Schottky diode.
Example PCB Layout
Top Layer
Bottom Layer
Innovative PowerTM
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