RFM31B Datasheet, PDF (14/63 Pages) List of Unclassifed Manufacturers – ISM RECEIVER

RFM31B
3.2. Operating Mode Control
There are three primary states in the RFM31B radio stat e machine:SHUTDOWN, IDLE, and RX (see Figure6).The
SHUTDOWN state completely shuts down the radio to minimize current consumption. There are five different
configurations/options for the IDLE state which can be selected to optimize the chip to the applications needs.
"Register 07h. Operating Mode and Function Control 1" controls which operating mode/state is selected with the
exception of SHUTDOWN which is controlled by SDN pin. The RX state may be reached automatically from any
of the IDLE states by setting the rxon bit in "Register 07h. Operating Mode and Function Control 1". Table 10
shows each of the operating modes with the time required to reach RX mode as well as the current consumption of
each mode.
The RFM31B includes a low-power digital regulated supply(LPLDO) which is internally connected in parallel to the
output of the main digital regulator. This common digital supply voltage is connected to all digital circuit blocks
including the digital modem, crystal oscillator, SPI, and register space.The LPLDO has extremely low quiescent
current consumption but limited current supply capability; it isused only in the IDLE-STANDBY and IDLE-SLEEP
modes. The main digital regulator is automatically enabled in all other modes.
SSHHUUTTDDOWWNN
IDLE*
RX
*Five Different Options for IDLE
Figure 6. State Machine Diagram
Table 10. Operating Modes Response Time
State/Mode
Shut Down State
Idle States:
Standby Mode
Sleep Mode
Sensor Mode
Ready Mode
Tune Mode
RX State
Response Time to RX Current in State /Mode [µA]
16.8 ms
15 nA
800 µs
800 µs
800 µs
200 µs
200 µs
NA
450 nA
1 µA
1 µA
800 µA
8.5 mA
18.5 mA
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