ak4140 AKM Semiconductor, Inc., ak4140 Datasheet - Page 19

• Manufacturer Part Number: ak4140
• Description: Digital Btsc Decoder
• Manufacturer: AKM Semiconductor, Inc.

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