MIC33M656 Evaluation Board User’s Guide
DS50002914A-page 16
2019 Microchip Technology Inc.
2.3.1.9
PCB LAYOUT CONSIDERATIONS WHEN DESIGNING WITH
MIC33M656
For the best performance with the minimum occupied board space, some proper layout
techniques should be applied. First, the input and output capacitors should be placed
as close to the MIC33M656 as possible and on the same layer as the IC. This will
ensure low ripple and lower switching noise. Then, vias must be used under the
MIC33M656, from its exposed pad to the GND plane, in order to improve heat
dissipation.
2.3.1.10 BENCH TESTING AT HIGH CURRENTS
When testing the MIC33M656 device at high load currents, or when checking the
overcurrent protection behavior, it may be necessary to remove the series ammeter
shown in
or to replace it with a very low-value shunt resistor. This is because
the internal resistance of many Digital Multimeters (DMMs) used for current
measurements is generally too high.
2.3.1.11
THERMAL CONSIDERATIONS
The MIC33M656 Junction-to-Ambient (
JA)
thermal resistance, as measured on the
Evaluation Board, is approxi31°C/W. Depending on the loading conditions,
ambient temperature and device settings, the junction temperature might exceed the
rated operating limit of +125°C due to internal power dissipation. Continuous operation
above the maximum operating limits stated in the data sheet should be avoided.
