DDP3310B datasheet(12/60 Pages) MICRONAS

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DDP 3310B

ADVANCE INFORMATION

Micronas

2.2. Analog Back-End

The digital RGB signals are converted to analog RGB

using three video digital to analog converters (DAC)

with 10-bit resolution. The analog RGB-outputs are

current outputs with current-sink characteristics. The

maximum current drawn by the output stage is

obtained with peak white RGB.

Each RGB signal has two additional DAC’s with 9-bit

resolution to adjust analog brightness (40 % of the full

RGB range) and cutoff / black level (60 % of the full

RGB range). An additional fixed current is applied for

the blanking level.

In order to define accurate color on different CRT dis-

plays, you must exactly adjust what color the CRT

phosphorous produces to display the color on screen.

To have the same colors for the life of the display, a

build-in automatic tube control loop checks and adjusts

the black level on every field and white point every third

field.

The back-end allows insertion of two external analog

RGB signals. The RGB signals are key-clamped and

inserted into the main RGB by the Fast-Blank switch.

The external RGB signals can be adjusted indepen-

dently as regarding DC-level (brightness) and magni-

tude (contrast). An external Half-Contrast signal can

be used to reduce the output current of the internal

RGB outputs to 50 %.

The controlling of the white-drive/analog brightness

and also the external contrast and brightness adjust-

ments is done via the internal processor.

2.2.1. Analog RGB Insertion

The DDP 3310B allows insertion of two external ana-

log RGB signals. Each RGB signal is key-clamped and

inserted into the main RGB by the Fast-Blank switch.

The selected external RGB input can be overlaid or

underlaid to the digital picture. The external RGB sig-

nals can be adjusted independently as regards DC

level (brightness) and magnitude (contrast).

It depends on the Fast-Blank input signals and the pro-

gramming of a number of I2C-register settings which

analog RGB input is selected. Both Fast-Blank inputs

must be either active-Low or active-High.

All signals for analog RGB insertion (RIN1/2, GIN1/2,

BIN1/2, FBLIN1/2, HCS) must be synchronized to the

horizontal flyback, otherwise a horizontal jitter will be

visible. The DDP 3310B has no means for timing cor-

rection of the analog RGB input signals.

2.2.2. Half-Contrast Control

Insertion of transparent text pages or OSD onto the

video picture is often difficult to read, especially if the

video contrast is high. The DDP 3310B allows contrast

reduction of the video background by means of a Half-

Contrast input (HCS pin). This input can be supplied

with a fast switching signal (similar to the Fast-Blank

input), typically defining a rectangular box in which the

video picture is displayed with reduced contrast. The

analog RGB inputs are still displayed with full contrast.

Fig. 2–8: Half-Contrast switch logic

Table 2–4: RGB Input Selection

Input Signals

I2C Settings

Analog

RGB Outputs

FBLIN1

FBLIN2

FBPOL

FBPRIO

Video

RGB input 2

RGB input 1

RGB input 2

RGB input 1

RGB input 2

RGB input 1

RGB input 2

Video

Note: with following I2C settings

FBFOH1 = FBFOH2 = FBFOL1 = FBFOL2 = 0

HCS

HCSEN

HCSFOH

HCS intern

HCSPOL

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