
Analog Devices
PRODUCT DESCRIPTION
The AD720 and AD721 RGB to NTSC/PAL Encoders convert red, green and blue color component signals into their corresponding luminance (baseband amplitude) and chrominance (subcarrier amplitude and phase) signals in accordance with either NTSC or PAL standards. These two outputs are also combined to provide a composite video output. All three outputs are available separately at voltages of twice the standard signal levels as required for driving 75 Ω reverse terminated cables. The AD721 also features a bypass mode, in which the RGB inputs may bypass the encoder section of the IC via three gain-of-two amplifiers suitable for driving 75 Ω reverse terminated cables.
FEATURES
Composite Video Output
Chrominance and Luminance (S-Video) Outputs
No External Filters or Delay Lines Required
Drives 75 Ω Reverse-Terminated Loads
Compact 28-Pin PLCC
Logic Selectable NTSC or PAL Encoding Modes
Automatically Selects Proper Chrominance Filter
Cutoff Frequency for Encoding Standard
Logic Selectable Encode or Power-Down Mode (AD720 Only)
Logic Selectable Encode or Bypass Mode (AD721 Only)
Low Power: 200 mW typical
APPLICATIONS
RGB to NTSC or PAL Encoding
Drive RGB Signals into 75 Ω Load (AD721 Only)