HA12181FP Datasheet, PDF (5/21 Pages) Hitachi Semiconductor – AM Radio Noise Reduction System

HA12181FP
Table of Pin Description and External Parts (cont)
No.
of
pin Name
DC
voltage
(V) (No
Function input)
Equivalent circuit
11 Gate Gate
pulse
genera-
tion
4.5V
0
11
12 Vth
Determi- 1.1
nation of
noise
detection
sensitivit
y
13 V_CC
V_CC
8.2
14 IF Det. IF AGC 3.3
detector
C507
2200p
R503
180k
12
R502
22k
—
External parts
Influence of External
parts
Larger Smaller
than
than
recom- recom- recom-
mended mended mended
No.
value value
value
R503 180 K Gate
Gate
C507
2200 P
pulse
width
become
wider.
pulse
width
become
narrow.
R502 22 K
Higher Lower
noise
noise
detection detection
sensitivity. sensitivity.
—
—
—
—
C503 0.01 µ —
—
15 AF
AGC
Time 0
constant
for AF
AGC
14
13
C503
0.01µ
15
C504
0.22µ
R505
47k
R505
C504
47 K
0.22 µ
Longer
time to
stabilize
AGC.
Miss-
operaton
in noise
detector.
Rev.2, Jun. 1997, page 5 of 21