AD724JR-REEL

Overview

The AD724JR-REEL is a low-cost RGB to NTSC/PAL encoder manufactured by Analog Devices Inc. It converts red, green, and blue color component signals into corresponding luminance and chrominance signals compliant with NTSC or PAL standards. The device operates from a single +5 V supply and accepts FSC or 4FSC clocks, or utilizes an on-chip oscillator with a parallel-resonant crystal. It provides composite video, separate Y/C (S-Video), and luminance outputs that can simultaneously drive 75 Ω reverse-terminated loads. The unit is housed in a compact 16-lead SOIC package.

Feature Summary

• Integrates RGB-to-YUV encoding matrix with matched luma and chroma delays for time-aligned outputs without external filters or delay lines.
• Features onboard DC clamps and logic-selectable NTSC or PAL encoding modes driven by TTL or CMOS compatible inputs.
• Supports multiple clocking options including FSC/4FSC CMOS clocks or internal oscillator with external crystal.
• Includes on-chip XNOR gate to generate composite sync from separate HSYNC and VSYNC signals.

Applications

• RGB to NTSC or PAL encoding
• Displaying VGA output on television monitors
• MPEG decoder video processing systems

Procurement Notes

Verify the specific reel quantity associated with the REEL suffix against current distributor listings. Confirm RoHS compliance status and lead-free solder availability prior to ordering. Ensure the selected variant matches the required temperature range and packaging format for the intended assembly process.

Selection Notes

Select this model when a compact 16-lead SOIC solution is required for converting analog RGB signals to standard definition video formats. Consider the power-down capability and minimal external component requirements for cost-sensitive designs. Verify compatibility with the system's available sync signals and clock frequencies before implementation.

Part Context

This component belongs to the AD724 series of video encoders produced by Analog Devices. The series includes variants such as the AD724JR and AD724JR-REEL7, all sharing the same core functionality within a 16-lead SOIC package. These devices are designed for commercial temperature ranges and provide integrated solutions for standard definition video generation.

Replacement Considerations

Direct substitutes include other AD724 variants like the AD724JR or AD724JR-REEL7 which share identical pinouts and electrical characteristics. Cross-referencing with similar RGB encoders requires verification of pin compatibility and signal levels.

FAQ

How does the AD724 handle sync signal input?

The device features an onboard XNOR gate that combines HSYNC and VSYNC inputs to create a composite sync signal. Alternatively, a CSYNC signal can be applied directly to the HSYNC pin while VSYNC is held high.

What clocking options are supported by the FIN pin?

The FIN pin accepts either an FSC or 4FSC CMOS clock. If no external clock is provided, it can connect to a parallel-resonant crystal to utilize the on-chip oscillator.

Can the AD724 drive standard video loads directly?

Yes, the outputs are amplified to drive 75 Ω reverse-terminated loads directly, compensating for signal loss in the termination resistors.