參數(shù)資料
型號(hào): ISL59112IEZ-T7
廠商: INTERSIL CORP
元件分類(lèi): 音頻/視頻放大
英文描述: 40MHz Rail-to-Rail Video Buffer
中文描述: 1 CHANNEL, VIDEO AMPLIFIER, PDSO6
封裝: ROHS COMPLIANT, PLASTIC, MO-203AB, SC-70, 6 PIN
文件頁(yè)數(shù): 4/6頁(yè)
文件大小: 203K
代理商: ISL59112IEZ-T7
4
FN6142.1
August 15, 2005
Application Information
The ISL59112 is a single supply rail-to-rail output buffer
achieving a -3dB bandwidth of around 40MHz and slew rate
of about 85V/μs while demanding only 2mA of supply
current. This part is ideally suited for applications with
specific micropower consumption and high bandwidth
demands. As the performance characteristics above and the
features described below, the ISL59112 is designed to be
very attractive for portable composite video applications.
The ISL59112 features a sync clamp and SAG network at
the output facilitating reduction of typically large AC coupling
capacitors. See Figure 3.
Internal Sync Clamp
The typical embedded video DAC operates from a ground
referenced single supply. This becomes an issue because
the lower level of the sync pulse output may be at a 0V
reference level to some positive level. The problem is
presenting a 0V input to most single supply driven amplifiers
will saturate the output stage of the amplifier resulting in a
clipped sync tip and degrading the video image. A larger
positive reference may offset the input above its positive
range.
The ISL59112 features an internal sync clamp and an offset
function to level shift the entire video signal to the best level
before it reaches the input of the amplifier stage. These
features are also helpful to avoid saturation of the output
stage of the amplifier by setting the signal closer to the best
voltage range.
The simplified block diagram of the ISL59112 in Figure 3 is
divided into four sections. The first, Section A is the Sync
Clamp. The AC coupled video sync signal is pulled negative
by a current source at the input of the comparator amplifier.
When the sync tip goes below the comparator threshold the
output comparator is driven negative, The PMOS device
turns on clamping sync tip to near ground level. AC Output
Coupling and the SAG Network
Composite video signals carry viable information at
frequencies as low as 30Hz up to 5MHz. When a video
system output is AC coupled it is critical that the filter
represented by the output coupling capacitor and the
surrounding resistance network provide a band pass
function with a low pass band low enough to exclude very
low frequencies down to DC, and with a high pass band pass
sufficiently high to include frequencies at the higher end of
the video spectrum.
Typically this is accomplished with 220μF coupling capacitor,
a large and somewhat costly solution providing a low
frequency pole around 5Hz. If the size of this capacitor is
even slightly reduced we have found that the accompanying
phase shift in the 50Hz to 100Hz frequency range results in
field tilt resulting in a degraded video image.
The internal SAG network of the ISL59112 replaces the
220μF AC coupling capacitor with a network of two smaller
capacitors as shown in Figure 4. Additionally, the network is
designed to place a zero in the ~30Hz range, providing a
small amount of peaking to compensate the phase response
associated with field tilt.
DC Output Coupling
The ISL59112 internal sync clamp makes it possible to DC
couple the output to a video load, eliminating the need for
any AC coupling capacitor saving board space and
additional expense for capacitors. Additionally, this solution
completely eliminates the issue of field tilt in the lower
frequency. The trade off is greater demand of supply current.
Typical load current for AC coupled is around 3mA
compared to typical 6mA used when DC coupling.
R
6
R
5
R
4
R
7
C
5
C
4
R
OUT
R
L
SAG
NETWORK
AC COUPLING
CAPACITOR
FIGURE 4. SAG NETWORK AND AC COUPLING CAPACITORS
-
+
TELEVISION
OR VCR
R
OUT
ENABLE
FIGURE 5. DC COUPLE
ISL59112
相關(guān)PDF資料
PDF描述
ISL59112 40MHz Rail-to-Rail Video Buffer
ISL5927EVAL1 Dual 14-Bit, +3.3V, 260+MSPS, High Speed D/A Converter
ISL5927IN Dual 14-Bit, +3.3V, 260+MSPS, High Speed D/A Converter
ISL5927 Dual 14-Bit, +3.3V, 260+MSPS, High Speed D/A Converter
ISL59421IUZ 865MHz Multiplexing Amplifier
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ISL59114 制造商:INTERSIL 制造商全稱(chēng):Intersil Corporation 功能描述:YC (S-video) to Composite Video Driver with LPF
ISL59114IRUZ 制造商:Intersil Corporation 功能描述:ISL59114IRUZ PB-FREE YC TO COMPOSITE VIDEO DRIVER WITH LPF - Bulk
ISL59114IRUZ-EVALZ 功能描述:EVAL BOARD FOR ISL59114IRUZ RoHS:是 類(lèi)別:編程器,開(kāi)發(fā)系統(tǒng) >> 評(píng)估演示板和套件 系列:* 標(biāo)準(zhǔn)包裝:1 系列:PCI Express® (PCIe) 主要目的:接口,收發(fā)器,PCI Express 嵌入式:- 已用 IC / 零件:DS80PCI800 主要屬性:- 次要屬性:- 已供物品:板
ISL59114IRUZ-T7 功能描述:IC VIDEO DRVR YC LPF 10-TQFN RoHS:是 類(lèi)別:集成電路 (IC) >> 線性 - 放大器 - 視頻放大器和頻緩沖器 系列:- 標(biāo)準(zhǔn)包裝:1,000 系列:- 應(yīng)用:驅(qū)動(dòng)器 輸出類(lèi)型:差分 電路數(shù):3 -3db帶寬:350MHz 轉(zhuǎn)換速率:1000 V/µs 電流 - 電源:14.5mA 電流 - 輸出 / 通道:60mA 電壓 - 電源,單路/雙路(±):5 V ~ 12 V,±2.5 V ~ 6 V 安裝類(lèi)型:表面貼裝 封裝/外殼:20-VFQFN 裸露焊盤(pán) 供應(yīng)商設(shè)備封裝:20-QFN 裸露焊盤(pán)(4x4) 包裝:帶卷 (TR)
ISL59114RUZ-T7 制造商:Intersil Corporation 功能描述:YC (S-video) to Composite Video Driver with LPF