140 MSPS Maximum Conversion Rate
500 MHz Analog Bandwidth
0.5 V to 1.0 V Analog Input Range
400 ps p-p PLL Clock Jitter
3.3 V Power Supply
2.5 V to 3.3 V Three-State CMOS Outputs
Demultiplexed Output Ports
Data Clock Output Provided
Low Power: 570 mW Typical
Internal PLL Generates CLOCK from HSYNC
Serial Port Interface
Supports Alternate Pixel Sampling for Higher-
RGB Graphics Processing
LCD Monitors and Projectors
Plasma Display Panels
100 MSPS/140 MSPS
Analog Flat Panel Interface
FUNCTIONAL BLOCK DIAGRAM
FILT SOGIN SOGOUT SDA SCL A0 A1 PWRDN REFOUT
The AD9884A is a complete 8-bit 140 MSPS monolithic analog
interface optimized for capturing RGB graphics signals from
personal computers and workstations. Its 140 MSPS encode
rate capability and full-power analog bandwidth of 500 MHz
supports display resolutions of up to 1280 × 1024 (SXGA) at
75 Hz with sufficient input bandwidth to accurately acquire and
digitize each pixel.
To minimize system cost and power dissipation, the AD9884A
includes an internal 1.25 V reference, PLL to generate a pixel
clock from HSYNC, and programmable gain, offset and clamp
circuits. The user provides only a 3.3 V power supply, analog
input, and HSYNC signals. Three-state CMOS outputs may be
powered by a supply between 2.5 V and 3.3 V.
The AD9884A’s on-chip PLL generates a pixel clock from the
HSYNC input. Pixel clock output frequencies range from
20 MHz to 140 MHz. PLL clock jitter is typically 400 ps p-p
relative to the input reference. When the COAST signal is pre-
sented, the PLL maintains its output frequency in the absence
of HSYNC. A 32-step sampling phase adjustment is provided.
Data, HSYNC and Data Clock output phase relationships are
always maintained. The PLL can be disabled and an external
clock input provided as the pixel clock.
A clamp signal is generated internally or may be provided by the
user through the CLAMP input pin. This device is fully program-
mable via a two-wire serial port.
Fabricated in an advanced CMOS process, the AD9884A is
provided in a space-saving 128-lead MQFP surface mount plastic
package and is specified over a 0°C to +70°C temperature range.
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.
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© Analog Devices, Inc., 2001