NXP Semiconductors AN11524, Примечание к применению

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Application note Rev. 1 — 17 February 2015 44 of 54
NXP Semiconductors
AN11524
NXQ1TXA6 Evaluation Board
9.4 NFC tap to power on
In NFC tap to power on mode, the charger is completed powered down when not charging
resulting in zero standby current. It can be seen with the CH 1 being 0 Volta in
Figure 35 .
When an NFC field is applied to the charging pad by an NFC enabled phone, the NFC
TAG chip TAG_VOUT, seen in CH 2, switches on the +12 V supply. After the DC-to-DC
converter has created a 3V3 supply and the NXQ1TXA6 charging controller has started,
the charging controller keeps the power switch active by enabling the PWR_ON signal as
observed in CH4.
CH1: +12 V - Switched 12 V supply
CH2: TAG_VOUT - Power harvesting output from NFC NTAG IC
CH3: PWR_ON - PWR_ON take over signal to maintain power
CH4: +3V3 - Charging controller power supply
Fig 35. NFC tap to power on
aaa-015920