IA4420 Datasheet, PDF (14/29 Pages) List of Unclassifed Manufacturers – Universal ISM Band FSK Transceiver

IA4420
3. Frequency Setting Command
Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
1 0 1 0 f11 f10 f9 f8 f7 f6 f5 f4 f3 f2 f1 f0
POR
A680h
The 12-bit parameter F (bits f11 to f0) should be in
the range of 96 and 3903. When F value sent is out
of range, the previous value is kept. The synthesizer
center frequency f can be calculated as:
0
f₀ = 10 * C1 * (C2 + F/4000) [MHz]
The constants C1 and C2 are
determined by the selected
band as:
Band [MHz] C1 C2
315
1 31
433
1 43
868
2 43
915
3 30
4. Data Rate Command
Bit 15 14 13 12 11 10 9
1100011
876543210
0 cs r6 r5 r4 r3 r2 r1 r0
POR
C623h
The actual bit rate in transmit mode and the expected bit rate of the received data stream in receive mode is determined by the 7-bit
parameter R (bits r6 to r0) and bit cs.
BR = 10000 / 29 / (R+1) / (1+cs*7) [kbps]
In the receiver set R according to the next function:
R= (10000 / 29 / (1+cs*7) / BR) – 1, where BR is the expected bit rate in kbps.
Apart from setting custom values, the standard bit rates from 600 bps to 115.2 kbps can be approximated with small error.
Data rate accuracy requirements:
Clock recovery in slow mode:
∆BR/BR
<
1/(29*N )
bit
Clock recovery in fast mode:
∆BR/BR
<
3/(29*N )
bit
BR is the bit rate set in the receiver and ∆BR is the bit rate difference between the transmitter and the receiver. N_bit is the maximal number
of consecutive ones or zeros in the data stream. It is recommended for long data packets to include enough 1/0 and 0/1 transitions, and be
careful to use the same division ratio in the receiver and in the transmitter.
5. Receiver Control Command
Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
1 0 0 1 0 p16 d1 d0 i2 i1 i0 g1 g0 r2 r1 r0
Bit 10 (p16): pin16 function select
POR
9080h
p16
Function of pin 16
0
Interrupt input
1
VDI output
14