![](http://datasheet.mmic.net.cn/310000/AD9985A_datasheet_16240231/AD9985A_2.png)
AD9985A
TABLE OF CONTENTS
Specifications.....................................................................................3
Rev. 0 | Page 2 of 32
Explanation of Test Levels...........................................................6
Absolute Maximum Ratings............................................................7
ESD Caution..................................................................................7
Pin Configuration and Function Descriptions.............................8
Design Guide...................................................................................11
General Description...................................................................11
Digital Inputs ..............................................................................11
Input Signal Handling................................................................11
Hsync, Vsync Inputs..................................................................11
Serial Control Port .....................................................................11
Output Signal Handling.............................................................11
Clamping.....................................................................................11
RGB Clamping........................................................................11
YUV Clamping.......................................................................12
Gain and Offset Control............................................................12
Auto Offset..............................................................................12
Sync-on-Green............................................................................13
Clock Generation .......................................................................13
12-Bit Divisor Register ..........................................................14
2-Bit VCO Range Register ....................................................14
3-Bit Charge Pump Current Register..................................14
5-Bit Phase Adjust Register...................................................14
Power Management....................................................................14
Timing..........................................................................................15
Hsync Timing............................................................................. 15
Coast Timing .............................................................................. 16
2-Wire Serial Register Map........................................................... 17
2-Wire Serial Control Register Detail Chip Identification... 19
PLL Divider Control.................................................................. 19
Clock Generator Control .......................................................... 20
Clamp Timing............................................................................. 20
Hsync Pulse Width..................................................................... 20
Input Gain................................................................................... 20
Input Offset................................................................................. 21
Mode Control 1.......................................................................... 21
2-Wire Serial Control Port............................................................ 26
Data Transfer via Serial Interface............................................. 26
Sync Slicer.................................................................................... 28
Sync Separator ............................................................................ 28
PCB Layout Recommendations.................................................... 29
Analog Interface Inputs............................................................. 29
Power Supply Bypassing............................................................ 29
PLL............................................................................................... 29
Outputs (Both Data and Clocks).............................................. 30
Digital Inputs.............................................................................. 30
Voltage Reference....................................................................... 30
Outline Dimensions....................................................................... 31
Ordering GuIde.......................................................................... 31
REVISION HISTORY
7/05—Revision 0: Initial Version