Verdin Carrier Board Design Guide
Preliminary
– Subject to Change
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important that this long press limit is set to a longer period (e.g. 7 seconds) than the 5 second limit
the Verdin module has. This makes sure that the module is performing the force OFF cycle before
the power button IC is removing VCC by the long press event.
3.4.1.3
Reference Schematics
Place enough power supply bypass capacitors on the voltage inputs of the peripheral devices (see
Toradex Layout Design Guide). Place a bypass capacitor on the power input pins of the Verdin
module. Be aware of the total capacity on a voltage rail when switching the voltage. If the rails are
switched on too fast, the inrush current for charging all the bypass capacitors can be very high.
This can produce unacceptable disturbances or can trigger an over-current protection circuit. In
such cases, tweak the soft start functions of the switches and regulators (if available).
For designing the power supply on the carrier board, a current consumption budget needs to be
considered. In this approach, the Verdin module is powered from the 5V rail. This means the
consumption of the module needs to be in the budget of the 5V buck converter. The current
consumption of the module that should be put into the budget depends whether the carrier board
should be designed for one specific module or should be compatible with multiple Verdin modules.
The Verdin module are thermally designed for dissipating up to 5W continuously. However, this
means that the peak power consumption and the peak current consumption can be higher. To be
compatible with all existing and future Verdin modules, it is recommended to design for at least
10W peak module power.
The reference schematic below contains the power button IC circuit and the major buck converters.
Additional schematics and design files of the different Verdin carrier boards are freely available on
the Toradex developer website.