Filter
Top Products
Si4421
AC Characteristics (PLL parameters)
Symbol Parameter Conditions/Notes Min Typ Max Units
f
ref
PLL reference frequency (Note 2) 9 10 11 MHz
433 MHz band, 2.5 kHz resolution 430.24 439.75
868 MHz band, 5.0 kHz resolution 860.48 879.51
f
o
Receiver LO/Transmitter carrier
frequency
915 MHz band, 7.5 kHz resolution 900.72 929.27
MHz
t
lock
PLL lock time
Frequency error < 1kHz
after 10 MHz step
30 µs
t
stP
PLL startup time (Note 10) With a running crystal oscillator 200 300 µs
AC Characteristics (Receiver)
Symbol Parameter Conditions/Notes Min Typ Max Units
mode 0 67
mode 1 134
mode 2 200
mode 3 270
mode 4 340
BW Receiver bandwidth
mode 5 400
kHz
BR
RX
FSK bit rate (Note 10) With internal digital filters 0.6 115.2 kbps
BRA
RX
FSK bit rate (Note 10) With analog filter 256 kbps
P
min
Receiver Sensitivity
BER 10
-3
, BW=67 kHz, BR=1.2 kbps,
868 MHz Band (Note 3)
-110 dBm
AFC
range
AFC locking range
δf
FSK
: FSK deviation in the received
signal
0.8
·
δf
FSK
IIP3
inh
Input IP3
In band interferers in high bands
(868 MHz, 915 MHz)
-21 dBm
IIP3
outh
Input IP3 Out of band interferers l f-f
o
l
> 4 MHz -18 dBm
IIP3
inl
IIP3 (LNA –6 dB gain)
In band interferers in low band (433
MHz)
-15 dBm
IIP3
outl
IIP3 (LNA –6 dB gain) Out of band interferers l f-f
o
l
> 4 MHz -12 dBm
P
max
Maximum input power LNA: high gain 0 dBm
Cin RF input capacitance 1 pF
RS
a
RSSI accuracy ± 6 dB
RS
r
RSSI range 46 dB
RS
ps
RSSI power supply dependency
When input signal level lower than -54
dBm and greater than -100 dBm
+35 mV/V
C
ARSSI
Filter capacitor for ARSSI 1 nF
RS
step
RSSI programmable level steps 6 dB
RS
resp
DRSSI response time
Until the RSSI signal goes high after
the input signal exceeds the
preprogrammed limit C
ARRSI
= 4.7 nF
500 µs
P
sp_rx
Receiver spurious emission -60 dBm
Notes are on page 12.
10