si4420 Silicon Laboratories, si4420 Datasheet - Page 20

• Manufacturer Part Number: si4420
• Description: Si4420 Universal Ism Band Fsk Transceiver
• Manufacturer: Silicon Laboratories

Bits 8-4 (mp, m3 to m0): FSK modulation parameters:
The resulting output frequency can be calculated as:
where:
Bits 2-0 (p2 to p0): Output power:
The output power given in the table is relative to the maximum available power, which depends on the actual antenna impedance.
(See: Antenna Application Note: IA ISM-AN1)
11. Transmitter Register Write Command
With this command, the controller can write 8 bits (t7 to t0) to the transmitter data register. Bit 7 (el) must be set in Configuration Setting
Command.
12. Wake-Up Timer Command
The wake-up time period can be calculated by (m7 to m0) and (r4 to r0):
T
Note:
Software reset: Sending FE00h command to the chip triggers software reset. For more details see the Reset modes section.
wake-up
Bit
Bit
= M * 2
 For continual operation the et bit should be cleared and set at the end of every cycle.
 For future compatibility, use R in a range of 0 and 29.
f
f
Frequency Setting Command)
M is the four bit binary number <m3 : m0>
SIGN = (mp) XOR (FSK input)
15
15
out
0
1
1
p2
is the channel center frequency (see the
0
0
0
0
1
1
1
1
= f
R
0
[ms]
14
14
+ (-1)
0
1
p1
0
0
1
1
0
0
1
1
SIGN
p0
13
13
0
1
0
1
0
1
0
1
1
1
* (M + 1) * (15 kHz)
12
12
r4
Relative Output Power [dB]
1
11
11
r3
1
-12
-15
-18
-21
10
10
r2
-3
-6
-9
0
0
r1
9
9
0
r0
8
8
0
m7
t7
7
7
m6
t6
6
6
m5
P
t5
5
5
out
mp=0 and FSK=0
m4
mp=1 and FSK=1
t4
4
4
or
m3
t3
3
3
m2
t2
2
2
df
fsk
m1
t1
1
1
f
0
df
fsk
m0
t0
0
0
mp=0 and FSK=1
mp=1 and FSK=0
or
B8AAh
E196h
POR
POR
f
out
Si4420
20