RFM92 Datasheet, PDF (51/126 Pages) List of Unclassifed Manufacturers – Low Power Long Range Transceiver Module

RFM92W/93W V3.0
4.2.6. Startup Times
The startup time of the transmitter or the receiver is dependent upon which mode the transceiver was in at the beginning.
For a complete description, Figure 17 below shows a complete startup process, from the lower power mode “Sleep”.
Current
Drain
IDDR (Rx) or IDDT (Tx)
IDDSL
0
IDDST
TS_OSC
IDDFS
TS_OSC
+TS_FS
Sleep
mode
Stdby
mode
FSTx
FSRx
TS_OSC
+TS_FS
+TS_TR
TS_OSC
+TS_FS
+TS_RE
Transmit
Timeline
Receive
Figure 17. Startup Process
TS_OSC is the startup time of the crystal oscillator which depends on the electrical characteristics of the crystal. TS_FS is
the startup time of the PLL including systematic calibration of the VCO.
Typical values of TS_OSC and TS_FS are given in Section 2.3.
4.2.6.1. Transmitter Startup Time
The transmitter startup time, TS_TR, is calculated as follows in FSK mode:
TS _ TR = 5μs +1.25× PaRamp + ¹ ×Tbit
2
,
where PaRamp is the ramp-up time programmed in RegPaRamp and Tbit is the bit time.
In OOK mode, this equation can be simplified to the following:
TS _ TR = 5μs + ¹ ×Tbit
2
4.2.6.2. Receiver Startup Time
The receiver startup time, TS_RE, only depends upon the receiver bandwidth effective at the time of startup. When AFC is
enabled (AfcAutoOn=1) the AfcBw should be used instead of RxBw to extract the receiver startup time:
Page 51
Tel: [phone] Fax: [phone] E-mail: [e-mail] http://www.hoperf.com