RFM22B/23B
8.7. Low Duty Cycle Mode
The Low Duty Cycle Mode is available to automatically wake-up the receiver to check if a valid signal is available.
The basic operation of the low duty cycle mode is demonstrated in the figure below. If a valid preamble or sync
word is not detected the chip will return to sleep mode until the beginning of a new WUT period. If a valid preamble
and sync are detected the receiver on period will be extended for the low duty cycle mode duration (TLDC) to
receive all of the packet. The WUT period must be set in conjunction with the low duty cycle mode duration. The R
value (“Register 14h. Wake-up Timer Period 1”) is shared between the WUT and the TLDC. The ldc[7:0] bits are
located in “Register 19h. Low Duty Cycle Mode Duration.” The time of the TLDC is determined by the formula
below:
R
4 2
TLDC ldc [7 : 0 ]
ms
32 .768
Figure 30. Low Duty Cycle Mode
Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: sales@hoperf.com http://www.hoperf.com
54
HOPERF [ HOPERF ]
