RFM210W Datasheet, PDF (18/21 Pages) List of Unclassifed Manufacturers – Low-Cost Consumer Electronics Applications

RFM210W/RFM217W
5.9 Easy Duty-Cycle Configurations
When the user wants to take the advantage of maintaining the highest system stability and performance, and the power
consumption is not the first concern in the system, the Easy Configuration can be used to let the device to work in the duty-cycle
mode without complex calculations, the following is a good example:
TX Data
T = Packet Length (72 ms)
A missed packet
RX State
Data
(DOUT pin)
SLEEP, XTAL and TUNE
T = Sleep Time (3 ms) +
XTAL Stabilizing Time (310 us) +
Tuning Time (300 us) = 3.61 ms
RX
T = Rx Time (1000 ms)
output data corrupted
Two missed packets
time
output data corrupted
Figure 15. Tx and Rx relationship of Easy Configuration
In this example, the Tx device transmits the data at 1.2 ksps and there are 60 symbols in one data packet. Thus, the packet
length is 50 ms. The user can do the following:
„ Set the Sleep Time to the minimum value of 3 ms.
„ Set the Rx Time to 1 second which is much longer than the packet length.
„ Let the Tx device to send out 3 continuous data packets in each transmission.
Because the Sleep Time is very short, the non-receive time is only about 3.61 ms (the sum of the Sleep Time, XTAL stabilizing
time and the tuning time), which is much shorter than the packet length of 50 ms. Therefore, this non-receive time period will only
have a change to corrupt no more than 2 packets receiving. During the non-receive time period, the DOUT pin will output logic 0.
Because the Rx Time is very long, and 3 continuous data packets are sent in each transmission, there is at least 1 packet that
can be completely received by the device and sent out via the DOUT pin with no corruption. The external MCU will only need to
observe the DOUT pin status to perform data capturing and further data processing.
If the system power consumption is a sensitive and important factor in the application, the Precise Configuration can be used.
Also, based on the duty-cycle receive mode, the “Wake-On Radio” technique allows the device to even save more power. For the
precise duty-cycle configurations and the use of wake-on radio, please refer to the “AN108 RFM210W/RFM217W Configuration
Guideline”.
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