Enhanced Closed-Caption Decoder CMOS

The MC144144 is a Line 21 closed–caption decoder for use in television receivers or set–top decoders conforming to the NTSC standard. Capability for processing and displaying all of the latest standard Line 21 closed–caption format transmissions is included. The device requires a closed–caption encoded composite video signal, a horizontal sync signal, and an external keyer to produce captioned video. RGB and box signal outputs are provided, which along with the mode select, allow simple interfacing to either color or black–and–white TV receivers.

• Conforms to FCC Report and Order as Amended by the Petition for

Reconsideration on Gen. Doc. 91–1

• Conforms to EIA–608 for XDS Data Structure

• Supports Four Different Data Channels for Field 1 and Five Different Data

Channels for Field 2, Time Multiplexed within the Line 21 Data Stream:

Captions Utilizing Languages 1 and 2, Text Utilizing Languages 1 and 2

and XDS Support

• Output Logic Provides Hardware Underline Control and Italics Slant Generation

• Single Supply, Operating Voltage Range: 4.75 to 5.25 V

• Supply Current: 20 mA (Preliminary)

• Operating Temperature Range: 0 to 70°C

• Composite Video Input Range: 0.7 to 1.4 V p–p

• Horizontal Input Polarity: Either Positive or Negative

• Internal Timing and Sync Signals Derived from On–Chip VCO