VDP 3108
ADVANCE INFORMATION
MICRONAS INTERMETALL
18
e
key
c
10 bit
DAC
Video
3.8 mA
blank &
measurem.
timing
8 bit
ADC
measurm.
9 bit
U/I–DAC
3.8 mA
clamp
analog
R in
Sense
Input
analog
R out
analog
G out
analog
B out
analog
G in
analog
B in
m
digital
R in
H
V
10
9 bit
DAC
1.5 mA
digital
G in
digital
B in
9 bit
DAC
2.2 mA
blanking
750 uA
10 bit
DAC
Video
3.8 mA
10 bit
DAC
Video
3.8 mA
9 bit
U/I–DAC
3.8 mA
clamp
9 bit
U/I–DAC
3.8 mA
clamp
c
9 bit
DAC
2.2 mA
blanking
750 uA
c
9 bit
DAC
2.2 mA
blanking
750 uA
9 bit
DAC
1.5 mA
9 bit
DAC
1.5 mA
e
I/O
Fig. 2–22:
Analog back end
w
w
e
w
e
w
9 bit
DAC
1.5 mA
w
9 bit
DAC
1.5 mA
i
w
9 bit
DAC
1.5 mA
w
i
i
fast
blank in
b
e
w
b
e
w
b
white drive R
white drive G
white drive B
int . brightness
ext. contrast
ext. brightness
FP Interface
2.5.1. CRT Measurement and Control
The display processor is equipped with an 8 bit PDM-
ADC for all measuring purposes. The ADC is connected
to the Sense input pin, the input range is 0...1.5V. The
bandwidth of the PDM filter can be selected; the mea-
surement window is 19/9.5
μ
s for small/large bandwidth
setting. The input impedance is more than 1 M
.
Cutoff and white drive current measurement is carried
out during the vertical blanking interval. It is always using
the small bandwidth setting. The current range for the
cutoff measurement is set by connecting a sense resis-
tor to then MADC input. For the whitedrive measure-
ment, the range is set by using a sense resistor and the
range select switch 2 output pin. During the active pic-
ture the minimum and maximum beam current is mea-
sured. The measurement range can be set by using the
range select switch pin. The timing window of this mea-
surement is programmable. The intention is to automati-
cally detect letterbox transmission or to measure the ac-
tual beam current. All control loops are closed via the
external control microprocessor.
In each field two sets of measurements can be taken:
a) The picture tube measurement returns results for