DDP3310B Datasheet, PDF (17/60 Pages) Micronas – Display and Deflection Processor

ADVANCE INFORMATION
DDP 3310B
2.3.3. Soft Start/Stop of Horizontal Drive
In order to increase the energy supply of the horizontal
deflection stage smoothly, a soft start decreases the
drive frequency from 55 kHz to 31.25 kHz within
85 ms. The High time t_H is always 14.4 µs. This
means, the duty factor decreases from 79.2 % to 45 %
(see Fig. 2–14).
The soft stop is needed, when the protection circuitry
wants to turn off the H-Drive. It has the inverse behav-
ior of the soft start and ends with a High level at the
HOUT Pin.
t_H = 14.4 µs
T=1/55 kHz
85 ms
...
... ...
Fig. 2–14: Soft start with a duty factor of 14.4/32
t_H = 14.4 µs
T = 1/31.25 kHz
Table 2–5: Allowed Horizontal Frequencies
Supply
Clock
(MHz)
27
27
27
27
27
27
32
32
32
32
32
40.5
Pixels per Main
Line
Clock
Supply Clk (in MHz)
864
40.5
858
40.5
800
40.5
768
40.5
720
40.5
712
40.5
1024
40.0
944
40.0
912
40.0
852
40.0
844
40.0
1296
40.5
Pixels per
line
Main Clk
1296
1287
1200
1152
1080
1068
1280
1180
1140
1065
1055
1296
Horizontal
Frequency
(Hz)
31.24968
31.46853
33.750
35.15625
37.500
37.92135
31.24952
33.89776
35.08747
37.55869
37.91469
31.24968
Minimum
H-Drive
Period
(in µs)
29.60
29.60
28.80
27.80
25.60
25.60
29.60
28.80
27.80
25.60
25.60
29.60
Maximum
H-Drive
Period
(in µs)
34.40
34.40
30.60
29.20
28.00
28.00
34.40
30.60
29.20
28.00
28.00
34.40
HFREQ
(I²C)
000
010
100
001
101
110
000
100
001
101
110
000
Micronas
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