NTE NTE844 Datasheet

NTE844

Integrated Circuit

Single Chip TV Chroma/Luminance Processor

Description:

The NTE844 is an integrated circuit in a 28–Lead DIP type package and contains all the required cir­cuits functions between the video detector and the picture tube RGB driver stages of a color television
receiver . The NTE844 decodes the chrominance signals and then produces three different color sig­nals that are internally combined with the luminance to develop the RGB signals. The picture satura­tion, hue and brightness DC controls are externally adjustable. The AFPC, ACC, Dynamic flesh con­trol, Beam limiting and Gate black level (Brightness)control are servo loops used to stabilize the RGB
output and reduce frequent manual adjustment. The automatic beam limiter circuit reduces picture
contrast and brightness to prevent excessive drive output at the picture tube.

Features:

D All chroma processing and demodulating circuitry on a single chip.
D Phase–locked subcarrier regeneration utilizing sample–and–hold techniques.
D Supplementary ACC with overload detector
D Linear DC controls for chroma gain and tint
D Dynamic “flesh correction”
D Balanced chroma demodulators with low output impedance for direct coupling
D Internal RF filtering
D Few external components
D Automatic beam limiter
D Chroma luminance tracking picture control

Absolute Maximum Ratings:

DC Supply Voltage Between Pin23 and Pin8 14.0V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Device Dissipation (Up to TA = +55°C), P

Derate Above TA = +55°C 13.3mW/°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operating Ambient Temperature Range, T
Storage Temperature Range, T
Lead Temperature (During Soldering, 1/16” from case, 10sec max), T

stg

D

opr

–40° to +85°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

–65° to +150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

L

1.27W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

+265°C. . . . . . . . . . . . . . . . .

Typical Performance Characteristics:

Function Typical Data

Nominal Supply 11.2V
Nominal Dissipation 500mW
Oscillator Stability

Supply Variation 10

–14

V 5Hz

Variation with Temperature

(∆T = +50°C) 25Hz

AFPC Characteristics

DC Loop Gain 33Hz/Degree

Pull–In Range ±500Hz

ACC Characteristic

100% Chroma Input Level 250mV

on Red Bar

p–p

3dB Point at 20% Nominal Input Level
Hue–Control Range 100°
Saturation–Control Range 40dB Min

Relative

Demodulator Characteristics:

Amplitude Angle

R – Y 1.0 93°

B – Y 1.2 2°

G – Y 0.3 258°
Bandwidth (Chroma) 900kHz
Flesh Control Primary Control in the +1 Half–Plane
Chroma Overload Control Two Levels
Picture Control 40dB
Brightness Control Black Level Clamped on 3V to 5V Level
Beam Limiting On Picture and Brightness Controls
Luma Bandwidth 5MHz Min
Sandcastle Input

1.2V to 2.3V Blanking

> 3.3V Burst gate
Maximum Linear Output

R 5V
G 3V
B 3.7V