sx1231h Semtech Corporation, sx1231h Datasheet - Page 37

• Manufacturer Part Number: sx1231h
• Description: Low Power Integrated Uhf Transceiver With On-chip +20dbm Pa
• Manufacturer: Semtech Corporation

The different timings shown above are as follows:
Note
Rev 1 - Oct 2011
ADVANCED COMMUNICATIONS & SENSING
(sequencer or user)
Rx startup request
XO Started and
ModeReady
RxReady
PLL is locked
Group delay of the analog front end:
Channel filter’s group delay in FSK mode:
Channel filter’s group delay in OOK mode:
DC Cutoff’s group delay:
PLL lock time after AFC adjustment:
AFC sample time:
RSSI sample time:
RxReady
ModeReady
XO Started and PLL is locked
The above timings represent maximum settling times, and shorter settling times may be observed in real cases
Analog FE’s
group delay
(sequencer or user)
Rx startup request
Tana
ModeReady
RxReady
XO Started and PLL is locked
Channel Filter’s
group delay
Tcf
Analog FE’s
group delay
(sequencer or user)
Rx startup request
Tana
group delay
DC Cutoff’s
Tdcc
Channel Filter’s
group delay
Figure 18. Rx Startup - No AGC, no AFC
sampling
Analog FE’s
group delay
Tcf
RSSI
Trssi
Figure 20. Rx Startup - AGC and AFC
Figure 19. Rx Startup - AGC, no AFC
Tana
Received Packet Preamble may start
sampling
RSSI
Trssi
group delay
DC Cutoff’s
Channel Filter’s
Tpllafc = 5 / PLLBW (PLLBW = 300 kHz)
Tafc = 4 x Tbit
Trssi = 2 x int(4.RxBw.Tbit)/(4.RxBw)
TS_RE_AGC&AFC
Tdcc = max(8 , 2^(round(log2(8.RxBw.Tbit)+1)) / (4.RxBw)
Tdcc
Tana = 20 us
Tcf = 21 / (4.RxBw)
Tcf = 34 / (4.RxBw)
group delay
Channel Filter’s
Tcf
group delay
Tcf
TS_RE_AGC
sampling
TS_RE
RSSI
Trssi
Page 37
Received Packet Preamble may start
DC Cutoff’s
group delay
DC Cutoff’s
group delay
sampling
Tdcc
Tdcc
RSSI
Trssi
sampling
sampling
RSSI
Trssi
RSSI
(also denoted TS_AFC in the general specification)
Trssi
Channel Filter’s
group delay
Received Packet Preamble may start
Tcf
The LNA gain is adjusted by
the AGC, according to the
sampling
AFC
Tafc
RSSI
Trssi
RSSI result
Tpllafc
PLL
lock
DC Cutoff’s
group delay
Tdcc
Channel Filter’s
group delay
Reception of Packet
Tcf
sampling
RSSI
Trssi
(aka TS_RSSI)
group delay
DC Cutoff’s
Tdcc
The LNA gain is adjusted by
Reception of Packet
the AGC, according to the
SX1231H
RSSI result
Reception of Packet
Carrier Frequency is adjusted
DATASHEET
www.semtech.com
by the AFC