Circuit Descriptions
7.
7.3
DC/DC Converters
The on-board DC/DC converters deliver the following voltages
(depending on set execution):
•
+STB_PWR, permanent voltage for the Stand-by Power
system and WIFI.
•
+3V3SB,voltage for scaler,IR/LED reciver,Key board
•
+12V, input from the power supply for the panel
common(active mode)
•
LBN power, input from the power supply for LNB supply
•
LDO_PWR,DVDD3V3, voltage for EMMC when TV on
•
VCCK, voltage for DDR when TV on
•
AVD3V3,AVDD1V0, supply voltage for scaler MT5593
•
+5V_SW, input intermediate supply voltage for USB
Power/SPDIF/CI
•
+3V3_TUNER, supply voltage for tuner
•
DVDD3V3, voltage for IC MT5800/EMMC when TV on
•
PVDD from the power +12V_AU for the AUDIO AMP
•
+1.2V_T2, +3.3VA_T2 voltage for Demodulator IC channel
decoder.Wi-Fi_VCC,voltage for WIFI
•
+1.8V, voltage for EMMC when TV on
•
Wi-Fi_VCC, voltage for WIFI
Figures gives a graphical representation of the DC/DC
converters with its current consumptions :
Figure 7-3 DC/DC converters
15
5.2V
-
NC
-
16
5.2V
-
FLAG
-
Number
Connector
CN9101
CN8602
CN9101
CN8603
Description
to SSB
to panel
to SSB
to panel
Pin
16
6
16
12
12V_AUDIO
FB603
PVDD
FB604
U202
LNB power
Q103
USB power
U114
TH1
CI_power
U712
+12V
U704
Vcck
AVDD1V2
U701
U705
+5V_SW
AVDD3V3
U707
DVDD3V3
+1.8V
U703
DDRV
U702
Tuner3.3V
STB_PWR
3V3SB
WiFi_Vcc
FB710
D701
FB708
Q702
PANEL_VCC
20220_203.eps