AD723ARU

Overview

The AD723ARU is a low-cost, fully integrated RGB-to-NTSC/PAL encoder manufactured by Analog Devices Inc. It converts analog red, green, and blue component signals into luminance (Y) and chrominance (C) for NTSC or PAL television displays. The device operates on a single supply voltage ranging from 2.7 V to 5.5 V and features current output drivers optimized for driving 75 Ω loads. Key specifications include a typical quiescent current of 16 mA with no external loads and a power-down current of less than 1 µA. It supports both composite video and S-video outputs, incorporates smart load detect functionality for self-power-down of unused drivers, and includes an integrated delay line with auto-tuned filters.

Feature Summary

• Integrates RGB-to-YUV encoding matrix with luminance and chrominance signal paths for direct NTSC/PAL conversion.
• Features smart load detection that automatically powers down unused output drivers to minimize energy consumption.
• Includes a logic-controlled triple switch at the input to manage differing load conditions when an RGB monitor is disconnected.
• Provides an optional luminance trap tap to reduce cross-color artifacts caused by subcarrier frequency information in the Y signal.

Applications

• TV Out for Personal Computers and Laptops
• Digital Cameras
• Set-Top Boxes
• Video Games
• Internet Appliances

Procurement Notes

Verify the specific ordering suffix RU-28 corresponds to the 28-Lead TSSOP package configuration required for your PCB layout. Confirm the temperature range specification matches your operational environment requirements before finalizing procurement orders.

Selection Notes

Select this component when a cost-effective solution for converting analog RGB signals to standard definition video is required. Ensure the design accommodates the necessary external gain setting resistors and clock frequencies (4FSC) specified in the datasheet for proper timing alignment.

Part Context

The AD723ARU belongs to the AD723 family of video encoders produced by Analog Devices Inc. This series focuses on providing integrated solutions for standard definition video encoding, distinguishing itself through low power consumption and built-in load detection capabilities suitable for portable and consumer electronics applications.

Replacement Considerations

The AD723ARU-REEL is a verified reel-packaged substitute offering identical electrical characteristics and pinout compatibility within the same package type.

FAQ

How does the AD723 handle power consumption when only one video output is used?

The device utilizes a smart load detect feature that periodically checks for the presence of a load. If only one output driver is active, the unloaded channel is automatically powered down to conserve energy.

What is the function of the YTRAP pin?

The YTRAP pin provides a filter tap for connecting an external L-C resonant network. This network can be tuned to null out the luminance response at the chrominance subcarrier frequency to eliminate cross-color artifacts.

How is the TV presence detected by the AD723?

The AD723 monitors the DC level at the output pins. If a load is removed, the voltage changes, causing the TVDET flag to go low. This allows the system to determine if a TV is connected without powering up the entire chip continuously.