ASAHI KASEI
[AK4140]
NOISE bit: Noise Detection
noise signal
Detected
NOISE bit
1
0
Not detected
Table 7. Noise Detection
0 Æ 1 :
1 Æ 0 :
Noise Level ≥ Noise Threshold Level (NTHR1,0 bit)
+ Noise Hysteresis Level (NHYS1,0 bit) / 2 (in dB)
Noise Level
< Noise Threshold Level (NTHR1,0 bit)
- Noise Hysteresis Level (NHYS1,0 bit) / 2 (in dB)
Hysteresis Level
(Controlled by PHYS1-0,
SHYS1-0, NHYS1-0 bits)
1
Threshold Level
(Controlled by PTHR1-0,
STHR1-0, NTHR1-0 bits)
0
Input Level (Pilot/SAP/Noise) [dB]
Figure 11. Pilot, SAP, Noise Detection Function
Pilot/SAP/Noise Detection Threshold Control
PTHR1 bit
PTHR0 bit
Threshold Level (typ)
-1.5dB
0
0
1
1
0
1
0
1
-3dB
-6dB (default)
-9dB
0dB= full scale of 1fH Pilot tone
Table 8. Pilot(fH) Threshold Level Control
MS0547-E-01
2007/03
- 19 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
