Overview
The AD725AR-REEL, produced by Analog Devices Inc., is a low-cost, general-purpose RGB to NTSC/PAL encoder. This integrated circuit converts red, green, and blue color component signals into their corresponding luminance (baseband amplitude) and chrominance (subcarrier amplitude and phase) signals, adhering to either NTSC or PAL video standards. The device combines these signals to provide a composite video output, making it suitable for various video encoding applications. It operates on a single +5V supply and features low power consumption, with a power-down mode that reduces current to less than 1 μA.
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| SIGNAL INPUTS (RIN, GIN, BIN) | Input Amplitude Full Scale | 0.714 | mV p-p | ||
| Black Level | 0.8 | V | |||
| Input Resistance | 1 | MΩ | |||
| Input Capacitance | 5 | pF | |||
| LOGIC INPUTS (HSYNC, VSYNC, 4FSC, CE, STND) | Logic Low Input Voltage | 1 | V | ||
| Logic High Input Voltage | 2 | V | |||
| Logic Low Input Current (DC) | 1 | μA | |||
| Logic High Input Current (DC) | 1 | μA | |||
| VIDEO OUTPUTS | Luminance (LUMA) Bandwidth, –3 dB (NTSC) | 4.4 | MHz | ||
| Luminance (LUMA) Bandwidth, –3 dB (PAL) | 5.2 | MHz | |||
| Gain Error | -7 | +7 | % |
Key Features
- Composite Video Output: Both NTSC and PAL standards supported.
- Chrominance and Luminance (S-Video) Outputs.
- Luma Trap Port to eliminate cross color artifacts.
- TTL Logic Levels.
- Integrated Delay Line and Auto-Tuned Filters.
- Drives 75 Ω reverse-terminated loads.
- Low Power +5 V Operation.
- Power-Down to <1 μA.
- Very Low Cost.
Applications
- RGB/VGA to NTSC/PAL Encoding.
- Personal Computers/Network Computers.
- Video Games.
- Video Conference Cameras.
- Digital Still Cameras.
Q & A
- What is the primary function of the AD725AR-REEL?
The AD725AR-REEL is an RGB to NTSC/PAL encoder that converts red, green, and blue color component signals into their corresponding luminance and chrominance signals.
- What video standards does the AD725AR-REEL support?
The AD725AR-REEL supports both NTSC and PAL video standards.
- What is the purpose of the Luma Trap Port?
The Luma Trap Port is used to eliminate cross color artifacts generated by subcarrier frequency components in the luminance signal.
- What is the typical input amplitude for the RGB signals?
The typical input amplitude for the RGB signals is 0.714 mV p-p.
- What is the power consumption of the AD725AR-REEL in power-down mode?
In power-down mode, the current consumption is less than 1 μA.
- What type of logic levels does the AD725AR-REEL use?
The AD725AR-REEL uses TTL logic levels.
- What is the bandwidth of the luminance output for NTSC and PAL?
The bandwidth of the luminance output is 4.4 MHz for NTSC and 5.2 MHz for PAL.
- What is the significance of the 4FSC input pin?
The 4FSC input pin accepts a frequency reference at four times the color subcarrier frequency, which is necessary for NTSC or PAL encoding.
- How does the AD725AR-REEL handle black level input?
The AD725AR-REEL has on-chip RGB input clamps to restore the DC level, and it does not require an external black level input.
- What are the differences between AD725AR-REEL7 and AD725ARZ?
The differences are primarily in the packaging and shipping configuration, with -REEL7 indicating parts are on a 7-inch reel, while the base functionality remains the same.
