SL1019P Datasheet, PDF (6/10 Pages) AUK corp – AM TUNER SYSTEM

Information in using IC(Continued)
C_D is 2000pF to 3000pF or there abouts
L₂ Damping(600kHz ~ 1400kHz) Reference Circuit: -15dB
Changing Circuit : -4dB
SL1019P
7. The L₂ is used to remove the SW band.
If the RF stage is double-tuned, the difference in sensitivity within the RF band almost
disappears. thereby leading to worse spurious characteristic.
8. The SL1019P contains 2-channel wide-band AGC.
The pin 6 detects and undesired signal within the RF band
and wide-band AGC is applied. This detection sensitivity is
determined inside the IC. The pin 2 detects and undesired
signal outside the RF band. This detection sensitivity is
W ide Be n d 2
AFC Input 6
RF AGC 1
W ide
Be n d
AGC
V ref
Signal
16 ^{16Me te r O u tpu t}
V cc
R9
Ge
RA
RB
C9
determined by R₃. When 1mVrms(f=1MHz) signal is applied
to pin 2, AGC operates.
9. In the AGC circuit of the test circuit the presence of an
A NT Da mp i n g 4
A NT
D a mp i n g
Dr i v e r
R A=4.3K
R B=3.0K
undesired signal of high strength within the receiving band
may cause the desired signal to be suppressed when the
desired signal is low or medium in strength. Shown below is
the circuit configuration where the necessary measures are taken against this
suppression.
10.The circuit shown below is available to stabilize the transient response of the signal
meter output at the search stop mode.
13
R10
R11
17
RF AGC
+
C18
C19
10K
1K
+
Signal during searching
from PLL
11. When using MW, no additional resistor is required
But when using LW(approximately 50℃ or greater), additionally connect a resistor of
27KΩ across pins 18 and 19 against increase in local OSC level.
12. For improvement in image frequency interference change the RF double tuning coil
as follows, and the image frequency interference becomes 63dB at f_r = 1400KHz (Q
point of the tuning circuit must not be decreased with tuning resistor 100KΩ )
KSI-W020-000
6