Circuit Descriptions
7.
7.4.7
Audio Mute circuit
This circuit will provide a “high-to-low” pulse when the +5 V
SSB power line goes low. This will trigger the related audio
mute circuit, preventing the audio circuit making uncontrolled
sounds.
Figure 7-10 Audio Mute circuit
7.4.8
AV33 and DV33 (U701)
The circuit around U701 will provide the main 3.3 V power
supply to the SSB.
Figure 7-11 AV33 and DV33 (U701)
7.4.9
Tuner
The tuner covers as followed:
•
VHF LOW BAND: from 49.75 MHz to 144.25 MHz.
•
VHF HIGH BAND: from 156.25 MHz to 448.25 MHz.
•
UHF BAND: from 456.25 MHz to 863.25 MHz.
I
2
C bus control of tuner, address selection.
19190_215_110905.eps
110905
L : Mute
L: MUTE
R628
10K 1/16W 5%
D601
NC/1N4148W
V_MUTE
R665
N
C
/100R
1/
16W
5
%
H: UN-MUTE
Q601
PMBS3904
5V_SW
POP_MUTE#
R621
470K 1/16W 5%
D603
BAT54C
ZD601
BZX84C3V6
1
3
R620
10K 1/16W 5%
Q605
PMBS3904
R630
N
C
/100R
1/
16W
5
%
Q604
PMBS3904
R624
2.2K 1/16W
Q602
PMBS3904
5VSB
D602
BAT54C
C604
1uF 16V
DVDD3V3_AMP
R629
1K 1/16W 5%
AMP_PD#
R622
100R 1/16W 5%
+12V
+12V
Q603
PMBS3906
1
2
3
V_MUTE
A_MUTE
R626
1K 1/16W 5%
C603
100N 50V
R618
47K 1/16W 5%
5VSB
H: ON
L: Pow er Dow n
R627
1K 1/16W 5%
V_MUTE
Q606
PMBS3904
5V_SW
R623
470OHM1/10W
V_MUTE
R619
10K 1/16W 5%
H : Un-mute
19190_209_110905.eps
110926
AVDD3V3
C721
10U 16V
3.3 V Main Power
3V3_BUCK
FB717
120R/3000mA
1
2
L701
2.2uH
FB716
120R/3000mA
1
2
C722
1UF 10V
C723
1UF 10V
3V3_BUCK
C717
10U 16V
C720
10U 16V
C719
10N 50V
R728
1K 1/16W 5%
R730
10K +-1% 1/16W
3V3_BUCK
5V_SW
R729
23.7K 1%
DVDD3V3
C718
10N 50V
U701
SC189ASKTRT
4
1
3
5
2
VOUT
VIN
EN
LX
GN
D
FB715
120R/3000mA
1
2