Telit Wireless Solutions NE310L2, Руководство по конструкции аппаратуры

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NE310L2 Hardware Design Guide
1VV0301711 Rev. 2 Page 26 of 64 2021-06-22

The placement of the power supply on the board should be done in such a way to
guarantee that the high current return paths in the ground plane are not
overlapped to any noise sensitive circuitry as the microphone amplifier/buffer or
earphone amplifier.
 The power supply input cables should be kept separate from noise sensitive lines
such as microphone/earphone cables.

The insertion of the EMI filter on the VBATT pins is suggested in those designs
where the antenna is placed close to battery or power supply lines. A ferrite bead
like Murata BLM18EG101TN1 or Taiyo Yuden P/N FBMH1608HM101 can be used
for this purpose.
The below figure shows the recommended circuit:
Figure 4: recommended circuit
RTC Supply
RTC is functional when NE310L2 is in PSM or OFF state and VBATT pin is supplied.
RTC settings are lost when VBATT supply is removed.
PWRMON Power-on monitor
PWRMON is always active (output high) when the module is powered ON (module
powered ON indication) and cannot be set to LOW level by any AT command.
This signal is present on pin R1.The operating range characteristics of PWRMON signal
are:
Item Min Typical Max
Output voltage 1.35V 1.8V 1.8V