參數(shù)資料
型號(hào): AD9985KSTZ-140
廠商: ANALOG DEVICES INC
元件分類: 其它接口
英文描述: 110 MSPS/140 MSPS Analog Interface for Flat Panel Displays
中文描述: SPECIALTY INTERFACE CIRCUIT, PQFP80
封裝: LEAD FREE, MS-026BEC, LQFP-80
文件頁數(shù): 28/32頁
文件大?。?/td> 349K
代理商: AD9985KSTZ-140
AD9985
Rev. 0 | Page 28 of 32
SYNC STRIPPER
ACTIVITY
DETECT
NEGCLAMP
COMP
SOG
HSYNC IN
ACTIVITY
DETECT
MUX 2
HSYNC OUT
PIXEL CLOCK
MUX 1
SYNC SEPARATOR
INTEGRATOR
VSYNC
SOG OUT
HSYNC OUT
VSYNC OUT
MUX 4
VSYNC IN
1/S
PLL
HSYNC
ACTIVITY
DETECT
AD9985
CLOCK
GENERATOR
POLARITY
DETECT
POLARITY
DETECT
POLARITY
DETECT
MUX 3
COAST
COAST
0
Figure 14. Sync Processing Block Diagram
Table 43. Control of the Sync Block Muxes via the Serial Register
Serial Bus
Mux No.
Control Bit
1 and 2
0EH: Bit 3
3
0FH: Bit 5
4
0EH: Bit 0
SYNC SLICER
The purpose of the sync slicer is to extract the sync signal from
the Green graphics channel. A sync signal is not present on all
graphics systems, only those with Sync-on-Green. The sync
signal is extracted from the Green channel in a two-step
process. First, the SOG input is clamped to its negative peak
(typically 0.3 V below the black level). Next, the signal goes to a
comparator with a variable trigger level, nominally 0.15 V above
the clamped level. The “sliced” sync is typically a composite sync
signal containing both Hsync and Vsync.
Control
Bit State
0
1
0
1
0
1
Result
Pass Hsync
Pass Sync-on-Green
Pass Coast
Pass Vsync
Pass Vsync
Pass Sync Separator Signal
SYNC SEPARATOR
A sync separator extracts the Vsync signal from a composite
sync signal. It does this through a low-pass filter-like or
integrator-like operation. It works on the idea that the Vsync
signal stays active for a much longer time than the Hsync signal,
so it rejects any signal shorter than a threshold value, which is
somewhere between an Hsync pulsewidth and a Vsync
pulsewidth.
The sync separator on the AD9985 is simply an 8-bit digital
counter with a 5 MHz clock. It works independently of the
polarity of the composite sync signal. (Polarities are determined
elsewhere on the chip.) The basic idea is that the counter counts
up when Hsync pulses are present. But since Hsync pulses are
relatively short in width, the counter only reaches a value of N
before the pulse ends. It then starts counting down, eventually
reaching 0 before the next Hsync pulse arrives. The specific
value of N will vary for different video modes, but will always
be less than 255. For example, with a 1 μs width Hsync, the
counter will only reach 5 (1 μs/200 ns = 5). When Vsync is
present on the composite sync, the counter will also count up.
However, since the Vsync signal is much longer, it will count to
a higher number M. For most video modes, M will be at least
255. So, Vsync can be detected on the composite sync signal by
detecting when the counter counts to higher than N. The
specific count that triggers detection (T) can be programmed
through the serial register (11H).
Once Vsync has been detected, there is a similar process to
detect when it goes inactive. At detection, the counter first resets
to 0, then starts counting up when Vsync goes away. Similar to
the previous case, it will detect the absence of Vsync when the
counter reaches the threshold count (T). In this way, it will
reject noise and/or serration pulses. Once Vsync is detected to
be absent, the counter resets to 0 and begins the cycle again.
相關(guān)PDF資料
PDF描述
AD9990 Dual Channel, 14-Bit CCD Signal Processor with V-Driver and Precision Timing
AD9991KCPRL 10-Bit CCD Signal Processor with Precision Timing Generator
AD9991KCP 10-Bit CCD Signal Processor with Precision Timing Generator
AD9991 10-Bit CCD Signal Processor with Precision Timing Generator
AD9992 12-Bit CCD Signal Processor with Precision Timing Generator
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD9990 制造商:AD 制造商全稱:Analog Devices 功能描述:Dual Channel, 14-Bit CCD Signal Processor with V-Driver and Precision Timing
AD9990BBCZ 功能描述:IC CCD SGNL PROCESSOR 112CSPBGA RoHS:是 類別:集成電路 (IC) >> 接口 - 傳感器和探測器接口 系列:- 其它有關(guān)文件:Automotive Product Guide 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:74 系列:- 類型:觸控式傳感器 輸入類型:數(shù)字 輸出類型:數(shù)字 接口:JTAG,串行 電流 - 電源:100µA 安裝類型:表面貼裝 封裝/外殼:20-TSSOP(0.173",4.40mm 寬) 供應(yīng)商設(shè)備封裝:20-TSSOP 包裝:管件
AD9990BBCZRL 功能描述:IC CCD SGNL PROCESSOR 112CSPBGA RoHS:是 類別:集成電路 (IC) >> 接口 - 傳感器和探測器接口 系列:- 其它有關(guān)文件:Automotive Product Guide 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:74 系列:- 類型:觸控式傳感器 輸入類型:數(shù)字 輸出類型:數(shù)字 接口:JTAG,串行 電流 - 電源:100µA 安裝類型:表面貼裝 封裝/外殼:20-TSSOP(0.173",4.40mm 寬) 供應(yīng)商設(shè)備封裝:20-TSSOP 包裝:管件
AD9991 制造商:AD 制造商全稱:Analog Devices 功能描述:10-Bit CCD Signal Processor with Precision Timing Generator
AD9991KCP 制造商:Analog Devices 功能描述:AFE Video 1ADC 10-Bit 3V 56-Pin LFCSP EP 制造商:Rochester Electronics LLC 功能描述:- Bulk