User's Guide

ATOP3.5G Product Description
80447ST10636A rev.10 – 2015-03-03
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Reserved. Page 30 of 66
Mod. 0808 2011-07 Rev.2
9.2 Current source
ATOP 3.5G handles all its voltage conversion internally.
For the Utility Processor, a separate input, VBAT_MC_SNK, is used. Internally, an LDO,
controlled by VDD_3V0_SRC_ENA (active HIGH, with internal pull up), converts it to the 3 V
required by the utility processor. As described in Figure 8, the output of the LDO is also available
externally to power external component, up to a maximum of 50 mA can be drawn, depending on
the operating temperature range and the VBAT_MC_SNK value. Other limiting values can be
found in Table 14.
Figure 8 ATOP 3.5G VDD_3V0_SRC current source
9.3 RTC
The MCU RTC is internally supplied by the output of the LDO described in Figure 8. It can also be
supplied by a separate battery such as a coin cell via VBAT_RTC_SNK such that the RTC is kept
alive in case of power loss.
9.4 ESD protection
All pins are tested against ESD according to HBM. Pins that have direct a connection to external world in the
application, such as antennas and battery charging, are tested against ESD following HMM models.
 Human Body Model (HBM): 2000 V requirements are fulfilled
 Human Metal Model (HMM), detailed list is as follows:
o CELL_ANT1 and CELL_ANT2 up to 4 kV
o VBAT_SNK, VBAT_MC_SNK, and VBAT_VCC_PA_SNK up to 4 kV
o For GPS_PAS _ANT and GPS_ACT_ANT up to 4 kV. For GPS_ACT_ANT an
external ESD protection diode is recommended if used externally
Charged Device Model (CDM) is considered not applicable for metal-shielded modules, such as OM12030.
9.5 NFC antenna design
Remark: This paragraph applies only to OM12030/1X0 (with X as defined in Section 5).
For NFC antenna design, refer to Ref [6] for antenna design and Ref [7] in case the application
requires to boost the NFC signal.