RX95HF Datasheet, PDF (8/44 Pages) STMicroelectronics – Near field communication transceiver for tag emulation

Power management and operating modes
3
Power management and operating modes
RX95HF
3.1
Operating modes
The RX95HF has 2 operating modes: Wait for Event (WFE) and Active. In Active mode, the
RX95HF communicates actively with an NFC reader or an external host (an MCU, for
example).
The RX95HF can switch from one mode to another.
Mode
Table 3. RX95HF operating modes and states
State
Description
Wait For
Event
(WFE)
Active
Power-up
This mode is accessible directly after POR.
Low level on IRQ_IN pin (longer than 10 μs) is the only wakeup
source. LFO (low-frequency oscillator) is running in this state.
Hibernate
Lowest power consumption state. The RX95HF has to be woken-up
in order to communicate. Low level on IRQ_IN pin (longer than 10
μs) is the only wakeup source.
Sleep/Field
Detector
Low power consumption state. Wakeup source is configurable:
– IRQ_IN pin
– Field Detector
LFO (low-frequency oscillator) is running in this state.
Ready
In this mode, the RX95HF waits for a command (PROTOCOLSELECT,
...) from the external host via the serial interface (SPI).
The RX95HF can communicate as a tag with an external reader. The
Tag Emulation tag application is located in the Host and communicates with the
RX95HF via the serial interface (SPI).
Hibernate, and Sleep/Field Detector states can only be activated by a command from the
external host. As soon as any of these three states are activated, the RX95HF can no longer
communicate with the external host. It can only be woken up.
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