Daewoo DTJ-28G8F, Service Manual

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IC description

Together with this pin, it can be used to drive symmetrical 
deflection amplifiers.

Pin 21

 - East/West Parabola Output 

EW

This pin supplies the parabola signal for the East/West 
correction. The drive signal is generated with 15-bit preci-
sion. The analog voltage is generated by a 4-bit current 
DAC with external resistor and uses digital noise-shaping.

Pin 22

 - DAC Current Reference 

XREF

External reference resistor for DAC output currents, typical 
10 k

§

Ù

, to adjust the output current of the D/A converters. 

(see recommended operation conditions). 
This resistor has to be connected to analog fround as 
closely as possible to the pin.

Pin 23

 - Scan Velocity Modulation Output 

SVM

This output delivers the analog SVM signal. The D/A con-
verters. At zero signal the output current is 50% of the 
maximum output current.

Pin 24,25,26

 - Analog RGB Output 

ROUT, GOUT, BOUT

These pins are the analog Red/Green/Blue outputs of the 
back-end. The outputs are current sinks.

Pin 27

 - Ground, Analog Back-end 

GNDO*

This pin has to be connected to the analog supply voltage. 
No supply current for the digital stages should flow through 
this line.

Pin 28

 - Supply Voltage, Analog Back-end 

VSUPO*

This pin has to be connected to the analog supply voltage. 
No supply current for the digital stages should flow through 
this line.

Pin 29

 - DAC Reference Decouplign/Beam Current Safety 

VRD/BCS

Via this pin, the DAC reference voltage is decoupled by an 
external capacitor. The DAC output currents depend on 
this voltage, therefore a pull-down transistor can be used 
to shut off all beam currents. A decoupling capacitor of 
4.7uF in parallel to 100uF (low inductance) is required.

Pin 30, 34

 - Fast-Blank Input 

FBLIN1/2

These pins are used to switch the RGB outputs to the 
external analog RGB inputs. FBLIN1 switches the RIN1, 
GIN1 and BIN1 inputs, FBLIN2 switches the RIN2, GIN2 
and BIN2 inputs. The active level (Low or High) can be 
selected by software.

Pin 31, 32, 33

 - Analog RGB Input1 

RIN1, GIN1, BIN1

These pin are used to insert an external analog RGB sig-
nal, e.g. from a SCART connector which can by switched 
to the analog RGB outputs with the Fast-Blank signal. 
The analog back-end provides separate brightness and 
contrast settings for the external analog RGB signals.

Pin 35, 36, 37

 - Analog RGB Input2 

RIN2, GIN2, BIN2

These pins are used to insert an external analog RGB sig-
nal, e.g. from a SCART connector which can by switched 
to the analog RGB outputs with the Fast-Blank signal. 
The analog back-end provides separate brightness and 
contrast settings for the external analog RGB signals.

Pin 38

 - Test Input 

TEST

This pin enables factory test modes. For normal operation 
it must be connected to ground.

Pin 39

 - Reset Input 

RESQ

A low level on this pin resets the DDP 3310B.

Pin 40

 - Adjustable DC Output 1 

PWM1

This output delivers a DC voltage with a resolution of 8 
bit, adjustable over the      bus. The output is driven by a 
push-pull stage. The PWM frequency is appr 79.4MHz. 

For a ripple-free voltage a first order lowpass filter with a 
corner frequency < 120 Hz should be applied.

Pin 41

 - Adjustable DC Output 2

 PWM2

See pin 40.

Pin 42

 - Half-Contrast Input 

HCS

Via this input pin the output level of the D/A-converted 
internal RGB signals can be reduced by 6dB. Inserted 
external analog RGB signals remain unchanged.

Pin 43...50

 - Picture Bus Chroma 

C0...C7

The Picture Bus Chroma lines carry the multiplexed color 
component data. For the 4:1:1 input signal (4-bit chroma) 
the pins C4...C7 are used.

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