AK2400 Datasheet, PDF (46/52 Pages) Asahi Kasei Microsystems – High integrated receiver for PMR-LMR

4) Noise Amp
The following gives a sample configuration of a BPF when input frequency is 31kHz.
Some parameters can be calculated using following (1) to (3) equations.
24 NAMPO C2
R3
C3 R1 C1
_
+ _{23 NAMPI}
R2
Noise Amp
AVSS
(1) 　f ₀

2π
1 _LSI
R₃ (R₁ // R₂ )C²
(2)　G_v

R₃
2R₁
(3)　Q²  ^R3
4(R₁ // R₂ )
C1=0.47uF
C2=C3=C=220pF
R1=10k
R2=5.6k
R3=150k
Figure 31 NAMPO, NAMPI
5) NRECTO pin
Rise time of noise detection is proportionate to C1=0.1μF and internal resistance 75kΩ
25 NRECTO
LSI
C1
AVSS
C1=0.1F
6) RSSIOUT pin
Figure 32 NRECTO
26 RSSIOUT
C1
LSI
R1
AVSS
R1=51kΩ
C1=1000pF
Figure 33 RSSIOUT
[AK2400]
014008989-E-01
46
2015/4