VDP313XY Ver la hoja de datos (PDF) - Micronas

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componentes Descripción

Fabricante

VDP313XY

Video Processor Family

Micronas 

ADVANCE INFORMATION

VDP 313xY

2.11.Video Back End

The digital RGB signals are converted to analog RGBs

using three video digital to analog converters (DAC)

with 10-bit resolution. An analog brightness value is

provided by three additional DACs. The adjustment

range is 40 % of the full RGB range.

Controlling the whitedrive/analog brightness and also

the external contrast and brightness adjustments is

done via the Fast Processor, located in the front-end.

Control of the cutoff DACs is via I2C-bus registers.

Finally cutoff and blanking values are added to the

RGB signals. Cutoff (dark current) is provided by three

9-bit DACs. The adjustment range is 60 % of full scale

RGB range.

The analog RGB-outputs are current outputs with cur-

rent-sink characteristics. The maximum current drawn

by the output stage is obtained with peak white RGB.

An external half contrast signal can be used to reduce

the output current of the RGB outputs to 50 %.

2.11.1.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

to 1.5 V. The bandwidth of the PDM filter can be

selected; it is 40/80 kHz for small/large bandwidth set-

ting. The input impedance is more than 1 MΩ.

Cutoff and whitedrive current measurement are carried

out during the vertical blanking interval. They always

use the small bandwidth setting. The current range for

the cutoff measurement is set by connecting a sense

resistor to the MADC input. For the whitedrive mea-

surement, the range is set by using another sense

resistor and the range select switch 2 output pin

(RSW2). During the active picture, the minimum and

maximum beam current is measured. The measure-

ment range can be set by using the range select switch

1 pin (RSW1) as shown in Fig. 2–1 and Fig. 2–18. The

timing window of this measurement is programmable.

The intention is to automatically detect letterbox trans-

mission or to measure the actual beam current. All

control loops are closed via the external control micro-

processor.

A

D

MADC

beam current

SENSE

RSW1 R2

RSW2 R3

R1

Fig. 2–1: MADC Range Switches

black

ultra black

CR + IBRM + WDRV⋅WDR

CR + IBRM

cutoff

R

white

drive

R

CG + IBRM

cutoff

G

CB + IBRM

cutoff

B

active measure-

ment resistor

R1||R2||R3

RSW1=on, RSW2=on

PICTURE MEAS.

Lines

PMSO

R1

R1||R3

RSW2

=on

TUBE MEASUREMENT

TML

Fig. 2–18: MADC Measurement Timing

R

G

B

R1||R2||R3

RSW1=on, RSW2=on

PICTURE MEAS.

PMST

Micronas

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