phyCARD-M [PCA-A-M1-xxx]
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PHYTEC Messtechnik GmbH 2010 L-750e_1
4.4
Supply Voltage for external Logic
The voltage level of the phyCARD's logic circuitry is VDD_3V3
(3.3V) and equals the supply voltage of the phyCARD-M. Thus
connecting external devices to the phyCARD-M does not require any
special precautions. This means that external devices could be
supplied from the same power source as the phyCARD-M.
Nonetheless we recommend to supply external devices with the
voltage (VCC_Logic) brought out at pins X2A5 and X2B5 of the
phyCARD-Connector and to use level shifters supplied with this
voltage at one of the supply rails if you want to keep your application
compatible to other phyCARDs with a different signal level. This
means that use of level shifters supplied with VCC_Logic allows
converting the signals according to the needs on the custom target
hardware independently from the phyCARD mounted. Alternatively
signals can be connected to an open drain circuitry with a pull-up
resistor attached to VCC_Logic.