RFM219SW

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Rev 1.0 | Page 20/35

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Turn on the radio (Forwards)

PUP

SLEEP

STBY

TUNE

RX

EEPROM

Turn off the radio (Backwards)

Figure 17. Device Operating State Machine

The below figure shows the switching time for a typical receive cycle, starting from the SLEEP mode. The power consumption is

also shown in the figure. They are measured when the device works in 868.35 MHz using FSK demodulation, with the Sleep

Timer turned off.

Current

5.7 mA

2.0 mA

520 uA

100 nA

SLEEP

STBY

TUNE

RX

Time

Wait for XTAL to get stable

Wait for PLL to settle

Wait for RF to settle

Receive incoming data

Time = Xtal Stabilizing Time <= 2.5 ms

Time = 300 us

Time = 20 us

Time determined by MCU, Rx Timer,

or receiving status

Send go_stby to switch to STBY

Send go_tune to switch to FS

Send go_rx to switch to RX

Can switch to any other state

Figure 18. Timing and Power from SLEEP to RX state

Power Up (PUP) State

Once the device is powered up, it will go through the Power Up (PUP) sequence which includes the task of releasing the

Power-On Reset (POR), turning on the crystal and calibrating the internal blocks. The PUP takes about 9.5 ms to finish. After that

the device is automatically switched to the SLEEP state.

SLEEP State

Most of the internal blocks are powered down including the crystal oscillator to save power. The SPI interface and control

registers are accessible. The FIFO is not accessible. The optional LPOSC and sleep timer can be turned on if the parameter of

‘Sleep Timer On-Off’ is set to ‘On’ on the RFPDK. The sleep current is less than 60 nA when the sleep timer is turned off and 440

nA when it is turned on.