HA12181FP Datasheet, PDF (12/21 Pages) Hitachi Semiconductor – AM Radio Noise Reduction System

HA12181FP
Example of Noise Reduction Effect
20
10
0
–10
–20
–30
–40
–50
V_CC=8.2V
AM SG : fc=999kHz, m=30%, fm=1kHz
Pulse : No input
Vout
NRoff
NRon
Pulse : No input
Two Signals dummy ANT.
50Ω
Pulse SG.
50Ω
AM SG.
16Ω ^16Ω 15p
30Ω
65p
16Ω
To
ANT
Pulse SG Output (EMF)
10µs
100mV_P-P
2µs
Figure.2
Noise
AM SG : fc=999kHz,
no mod.
Pulse SG :
Refer to Figure.2
–60
0
10 20 30 40 50 60 70 80 90 100 110 120
AM SG Output (EMF) (dBµ)
20
10
0
–10
–20
–30
–40
–50
V_CC=8.2V
AM SG : fc=999kHz, m=30%, fm=1kHz
Pulse : No input
Vout
NRoff
NRon
Two Signals dummy ANT.
50Ω
Pulse SG.
50Ω
AM SG.
16Ω ^16Ω 15p
30Ω
65p
16Ω
To
ANT
Pulse SG Output (EMF)
10µs
100mV_P-P
10µs
Figure.3
Noise
AM SG : fc=999kHz,
no mod.
Pulse SG :
Refer to Figure.2
–60
0
10 20 30 40 50 60 70 80 90 100 110 120
AM SG Output (EMF) (dBµ)
Rev.2, Jun. 1997, page 12 of 21