SAA7109 PHILIPS [NXP Semiconductors], SAA7109 Datasheet - Page 119

• Manufacturer Part Number: SAA7109
• Description: PC-CODEC
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
17.1
The analog output voltages are dependent on the total
load (typical value 37.5 ), the digital gain parameters and
the I
settings).
The digital output signals in front of the DACs under
nominal (nominal here stands for the settings given in
Tables 88 to 95 for example a standard PAL or NTSC
signal) conditions occupy different conversion ranges, as
indicated in Table 65 for a
Table 65 Digital output signals conversion range
17.2
Use separate ground planes for analog and digital ground.
Connect these planes only at one point directly under the
device, by using a 0
Use separate supply lines for the analog and digital supply.
Place the supply decoupling capacitors close to the supply
pins.
Use L
the decoupling capacitors to minimize radiation energy
(EMC).
2004 Mar 16
Digital settings
Digital output
Analog settings
Analog output
PC-CODEC
SET/OUT
2
C-bus settings of the DAC reference currents (analog
bead
Analog output voltages
Suggestions for a board layout
(ferrite coil) in each digital supply line close to
CVBS, SYNC TIP-TO-WHITE VBS, SYNC TIP-TO-WHITE
resistor directly at the supply stage.
see Tables 88 to 95
e.g. B DAC = 1FH
100
1.23 V (p-p)
100
1014
colour bar signal.
see Tables 88 to 95
e.g. G DAC = 1BH
119
1.00 V (p-p)
By setting the reference currents of the DACs as shown in
Table 65, standard compliant amplitudes can be achieved
for all signal combinations; it is assumed that in
subaddress 16H, parameter DACF = 0000b, that means
the fine adjustment for all DACs in common is set to 0%.
If S-video output is desired, the adjustment for the C
(chrominance subcarrier) output should be identical to the
one for VBS (luminance plus sync) output.
Place the analog coupling (clamp) capacitors close to the
analog input pins. Place the analog termination resistors
close to the coupling capacitors.
Be careful of hidden layout capacitors around the crystal
application.
Use serial resistors in clock, sync and data lines, to avoid
clock or data reflection effects and to soften data energy.
881
e.g. R DAC = G DAC = B DAC = 0BH
SAA7108E; SAA7109E
RGB, BLACK-TO-WHITE
see Table 83
0.70 V (p-p)
876
Product specification