CM3106 Datasheet, PDF (8/9 Pages) California Micro Devices Corp – 2 Amp Source/ Sink Bus Termination Regulator

V_DDQ
AV_IN
PV_IN
C_AVIN
47 mF
CM3106
APPLICATION INFORMATION
CM3106
V_DDQ
V_REF
AV_IN
V_SENSE
PV_IN
V_TT
GND
C_PVIN
47 mF
V_REF
C_REF
0.1 mF
V_TT
C_TT
220 mF
Figure 15. Typical Application Circuit
PCB Layout Considerations
The CM3106−12SB has a heat spreader attached to the
underneath of the PSOP−8 package in order for heat to be
transferred much easier from the package to the PCB. The
heat spreader is a copper pad of dimensions just smaller than
the package itself. By positioning the matching pad on the
PCB top layer to connect to the spreader during
manufacturing, the heat will be transferred between the two
pads. The drawing below shows the recommended PCB
layout. Note that there are six vias on either side to allow the
heat to dissipate into the ground and power planes on the
inner layers of the PCB. Vias can be placed underneath the
chip, but this can cause blockage of the solder. The ground
and power planes should be at least 2 sq in. of copper by the
vias. It also helps dissipation to spread if the chip is
positioned away from the edge of the PCB, and not near
other heat dissipating devices. A good thermal link from the
PCB pad to the rest of the PCB will ensure a thermal link
from the CM3106 package to ambient, q_JA, of around
40°C/W.
Figure 16. Recommended Heat Sink PCB Layout
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