RFM23 Datasheet, PDF (13/152 Pages) –

RFM23
2.1. Operating Modes
The RFM23 provides several modes of operation which can be used to optimize the power consumption of the
device application. Depending upon the system communication protocol, the optimal trade-off between the radio
wake time and power consumption can be achieved.
Table 9 summarizes the modes of operation of the RFM23. In general, any given mode of operation may be
classified as an Active mode or a Power Saving mode. The table indicates which block(s) are enabled (active) in
each corresponding mode. With the exception the Shutdown mode, all can be dynamically selected by sending the
appropriate commands over the SPI in order to optimize the average current consumption. An ―X‖ in any cell
means that, in the given mode of operation, that block can be independently programmed to be either ON or OFF,
without noticeably affecting the current consumption. The SPI circuit block includes the SPI interface and the
register space. The 32 kHz OSC circuit block includes the 32.768 kHz RC oscillator or 32.768 kHz crystal
oscillator, and wake-up timer. AUX (Auxiliary Blocks) includes the temperature sensor, general purpose ADC, and
low-battery detector.
Table 9. Operating Modes
Mode
Name
Digital LDO
Shutdown
OFF
(Register contents lost)
Standby
Sleep
Sensor
Ready
Tuning
ON
(Register contents retained)
Transmit
Receive
*Note: 28 mA at +13 dBm.
SPI
OFF
ON
ON
ON
ON
ON
ON
ON
Circuit Blocks
32 kHz
30 MHz
AUX
OSC
XTAL
OFF OFF OFF
OFF
ON
X
X
X
X
X
OFF
X
ON
X
X
X
X
OFF
OFF
OFF
ON
ON
ON
ON
PLL RA RX
IVDD
OFF OFF OFF 10 nA
OFF
OFF
OFF
OFF
ON
ON
ON
OFF OFF 400 nA
OFF OFF 800 nA
OFF OFF 1 μA
OFF OFF 600 μA
OFF OFF 9.5 mA
ON OFF 28 mA*
OFF ON 18.5 mA
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