10
PCB design guide
Optimization of PCB layout for high voltage, high current and high switching frequency applications is a critical
point. PCB layout is a complex matter as it includes several aspects, such as length and width of track and
circuitareas, but also the proper routing of the traces and the optimized reciprocal arrangement of the various
system elements in the PCB area.
A good layout can help the application to properly function and achieve expected performance. On the otherhand,
a PCB without a careful layout can generate EMI issues, provide overvoltage spikes due to parasitic inductance
along the PCB traces and produce higher power loss and even malfunction in the control and sensing stages.
In general, these conditions were applied during the design of the board:
•
PCB traces designed as short as possible and the area of the circuit (power or signal) minimized to avoid the
sensitivity of such structures to surrounding noise
•
Good distance between switching lines with high voltage transitions and the signal line sensitive to electrical
noise
•
The shunt resistors were placed as close as possible to the low side pins of the SLLIMM. To decrease the
parasitic inductance, a low inductance type resistor (SMD) was used
•
RC filters were placed as close as possible to the SLLIMM pins in order to increase their efficiency
10.1
Layout of reference board
All the components are inserted on the top of the board. Only the IPM module is inserted on the bottom to allow
the insertion of a suitable heatsink for the application.
Figure 17.
Silk screen and etch - top side
UM2702
PCB design guide
UM2702
-
Rev 1
page 26/34