AS3977-BQFU austriamicrosystems, AS3977-BQFU Datasheet - Page 37

• Manufacturer Part Number: AS3977-BQFU
• Description: IC RF TRANSMITTER FSK 16-QFN
• Manufacturer: austriamicrosystems

Specifications of AS3977-BQFU

• Frequency: 300MHz ~ 928MHz
• Applications: ISM
• Modulation Or Protocol: FSK
• Data Rate - Maximum: 100 kbps
• Power - Output: 10dBm
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 2 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 16-VQFN Exposed Pad, 16-HVQFN, 16-SQFN, 16-DHVQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Memory Size: -
• Current - Transmitting: -

AS3977
Data Sheet - A p p l i c a t i o n I n f o r m a t i o n
In case, the value of the A-counter is zero, the value of the A-counter has to be increased by M and the value of N has
to be decreased by one
In case, the N-counter is in the range from 16 to 31 and the value of the A-counter is less than N-counter-14:
Note: In case, no solution can be found for the wanted center frequency, it may help to modify the reference fre-
FSK Deviation Setting and Frequency Trimming
The frequency resolution Δf is determined by the reference frequency f
setting of INT<8> and can be calculated with following equation:
FSK Deviation Setting
The FSK deviation DF is given by the frequency resolution Δf and the setting of DF<7:0> and can be calculated with
the help of:
The deviation multiplier DM is determined by the setting of DF<7:6> according to the following table:
Frequency Trimming
Frequency trimming (e.g. in case a characterized crystal is used) can be done with the help of the (nominal) frequency
resolution Δf and without recalculating all the frequency settings. If the crystal error is known, the resulting error
the output frequency is also known. The ratio
positive,
A similar procedure can be performed to calibrate for initial frequency errors. Note that in both cases the resulting
value for FRAC<15:0> has to fulfil the conditions FRAC<15:0> - DF ≥ 0Η and FRAC<15:0> + DF ≤ FFFFH.
Gaussian Filter Clock Setting
The setting of GFCS<7:0> determines the clock frequency f
Ideally, f
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quency or INT<8>.
GF
---------- -
ε
Δf
RF
should be set to be 30*f
has to be subtracted from, in case the crystal error is negative it has to be added to FRAC<15:0>.
DF<7:6>
0 (00)
1 (01)
2 (10)
3 (11)
Mod
(f
Δf =
Mod
DF =
P
…modulation frequency).
f
---------- -
GF
ε
( ⋅
Δf
Δf DF
RF
=
INT <7:4> = AC - 1
INT
INT <3:0> = N - 16
⋅
can then be used to correct the error. In case the crystal error is
AC = AC + M
GFCS
N = N - 1
Revision 3.5
<8> +
<5:0> . DM
GF
<
f
1 )
REF
7
of the Gaussian filter according to
⋅
0 :
f
--------- -
2
REF
16
>
+
REF
1
, the selected frequency band and the
DM
16
1
2
4
(EQ 24)
(EQ 26)
(EQ 27)
(EQ 28)
(EQ 25)
ε
37 - 45
RF
in