NJM2211M NJR, NJM2211M Datasheet - Page 7

• Manufacturer Part Number: NJM2211M
• Description: IC FSK DEMOD/ TONE DECODER S014
• Manufacturer: NJR

Specifications of NJM2211M

• Function: Demodulator
• Current - Supply: 11mA
• Voltage - Supply: 4.5 V ~ 20 V
• Package / Case: 14-DMP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Gain: -
• Noise Figure: -
• P1db: -
• Lo Frequency: -
• Rf Frequency: -

■ APPLICATIONS
FSK Decoding
external components are defined as follows : R0 and C0 set the PLL center frequency. R1 sets the system bandwidth,
and C1 sets the loop filter time constant and the loop damping factor. C
the FSK data output. The resistor R
to facilitate rapid transition between output logic states.
Design Instructions
R0, R1, C0, C1 and CF. For a given set of FSK mark and space frequencies. f1 and f2, these parameters can be
calculated as follows :
1. Calculate PLL center frequency, f
2. Chose a value of timing resistor R0 to be in the range of 10kΩ to 100kΩ. This choice is arbitary. The recommended
3. Calculate value of C0 from Design Equation No.1 or from Typical Performance Characteristics :
4. Calculate R1 to give a ∆f equal to the mark-space deviation :
5. Calculate C1 to set loop damping. (See Design Equation No.4.)
6. Calculate Data Filter Capacitance, C
Note : All calculated component values except R0 can be rounded off to the nearest standard value, and R0 can be varied to fine-tune center
frequency through a series potentiometer, R
Ver.2003-12-09
Figure 2 shows the basic circuit connection for FSK decoding. With reference to Figures 1 and 2, the functions of
Recommended component values for some of the most commonly used FSK bauds are given in Table 1.
The circuit of Figure 2 can be tailored for any FSK decoding application by the choice of five key circuit components ;
value is R0 ≅ 20kΩ. The final value of R0 is normally fine-tuned with the series potentiometer, R
C0=1 / R0f
R1=R0 [f
Normally, ξ ≈ 1 / 2 is recommended
Then :C1=C0 / 4 for ξ =1 / 2
For R
C
f
0
F
=
(
in
f
F
1
=100kΩ. R
µ
+
2
) F
0
f
2
/ (f
0
=
1
Band
- f
Figure 2. FSK Decoding
2
)]
B
3
=510kΩ, the recommended value of C
Rate
B
0
x
(=510kΩ) from pin 7 to pin 8 introduces positive feedback across FSK comparator
(see Figure 2).
F
:
F
is :
Table 1. Recommended Value for FSK
300 Band
F
f2 =1270Hz
300 Band
f
f
1200 Band
f
f
1
2
1
2
FSK Band
1
=2025Hz
=2225Hz
=1200Hz
=2200Hz
=1070Hz
F
and R
(Ref. Fig. 2)
F
from a one pole post-detection filter for
C0=0.039µF C
C1=0.01µF R0=18kΩ
R1=100kΩ
C0=0.022µF C
C1=0.0047µF R0=18kΩ
R1=200kΩ
C0=0.027µF C
C1=0.01µF R0=18kΩ
R1=30kΩ
Component Values
F
F
F
=0.005µF
=0.005µF
=0.0022µF
x
.
- 7 -