9 A
UDIO
S
AMPLING
R
ATE AND
E
XTERNAL
PLL C
OMPONENT
C
ONFIGURATION
The decoder board has optional PLLs, which can be installed to provide the audio clock for the system. The initial version
of the STi5505 was not able to provide an audio clock for 96kHz support and an external PLL was used to support this.
This was fixed in the STi5505 later chip revisions and therefore no problems are expected in the STi5519. However, in
case a problem arises, the PLL circuit can be installed to provide a high quality clock particularly important in S/PDIF
applications.
In the default configuration, a small buffer chip is installed to buffer the audio clock between the STi5519 and the audio
DACs.
10 F
RONT
P
ANEL
10.1 VFD C
ONTROLLER
The VFD controller is a NEC uPD16311. This controller is not a processor, but does include a simple state machine
which scans the VFD and reads the front panel button matrix. The 16311 also includes RAM so it can store the current
state of all the VFD icons and segments. Therefore, the 16311 need only be accessed when the VFD status changes and
when the button status is read. The STI5519 can control this chip directly using PIO pins or can allow the front panel PIC
to control the VFD.
11 M
ISCELLANEOUS
F
UNCTIONS
11.1 R
ESET
C
IRCUITRY
Two different chips are supported to provide the power-on-reset and pushbutton reset function:
Telcom Semiconductor TC1270, or Dallas DS1811.
11.2 V
OLTAGE
R
EGULATORS
There are two +5V linear regulators to ge5V for the analog circuitry from +12V. A smaller DPAK surface mount
device can be used in most circumstances, but in applications were more than 150mA are required, a TO-220 through-
hole package can be used.
The STi5519 requires 2.5V to operate. This voltage is generated from +5V.
12 C
ONNECTORS
12.1 ATAPI D
RIVE
S
TANDARD
C
ONNECTOR
12.2 ST
I
5519 JTAG I
NTERFACE
12.3 SCART C
ONNECTORS
12.4 P
OWER
C
ONNECTOR
13.
VESTEL DVD DECODER CIRCUIT DESCRIPTION
13.1 POWER SUPPLY:
·
Socket PL1 is the 220VAC input.
·
Socket PL4 is used for the power button on the front panel.
·
2.5A fuse F1 is used to protect the device against short circuit.
·
Line filters and capacitors TR2, C2, TR4 and C3 are used to block the parasitic coming from the
mains. They also prevent the noise, produced in the circuit, from being injected to the line.
·
Voltage is rectified by using diodes D1, D5, D6 and D4. Using capacitor C1 (100
m
f) a DC voltage
is produced. (310- 320VDC).
