MRF89XAM8A-I Datasheet, PDF (42/140 Pages) Microchip Technology – Ultra Low-Power, Integrated ISM Band Sub-GHz Transceiver

MRF89XA
2.16 Receiver Configuration Registers
2.16.1 FILTER CONFIGURATION
REGISTER DETAILS
REGISTER 2-17: FILCREG: FILTER CONFIGURATION REGISTER (ADDRESS:0x10) (POR:0xA3)
R/W-1
R/W-0
R/W-1
R/W-0
R/W-0
R/W-0
R/W-1
R/W-1
PASFILV<3:0>
BUTFILV<3:0>
bit 7
bit 0
R = Readable bit
-n = Value at POR
r = Reserved
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-4
bit 3-0
PASFILV<3:0>: Passive Filter Value bits
These bits indicate the typical single sideband bandwidth of the passive low-pass filter.
1111 = 987 kHz
1110 = 676 kHz
1101 = 514 kHz
1100 = 458 kHz
1011 = 414 kHz
1010 = 378 kHz (default)
1001 = 321 kHz
1000 = 262 kHz
0111 = 234 kHz
0110 = 211 kHz
0101 = 184 kHz
0100 = 157 kHz
0011 = 137 kHz
0010 = 109 kHz
0001 = 82 kHz
0000 = 65 kHz
BUTFILV<3:0>: Butterworth Filter Value bits
These bits set the receiver bandwidth both in FSK and OOK mode.
BUTFILV<3:0> = 0011 Î f_c – f_o = 100 kHz (default)
f_c
=
f_o
+
200
kHz^∗
⎛
⎝
1-^f--x2--^{t-.-a-8-l--MM-----H-}H^{----zz-⎠⎞}
∗⎛
⎝
-1----+-----^v---^a---^l--⁽---^B--8--^U----^T----^F----^I--^L----^V----⁾-_⎠⎞
Where,
BUTFILV <3:0> is the value in the register
f_c is the cut-off frequency
f_o is the local oscillator frequency (center frequency)
f_xtal is the crystal oscillator frequency
Note: f_c – f_o = 100 kHz only when f_xtal = 12.8 MHz.
DS70622C-page 42
Preliminary
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