- 您現在的位置：買賣IC網 > PDF目錄373978 > ADD8704ACPZ-REEL7 (ANALOG DEVICES INC) 16 V Quad Operational Amplifier PDF資料下載
參數資料
| 型號： | ADD8704ACPZ-REEL7 |
| 廠商： | ANALOG DEVICES INC |
| 元件分類： | 運動控制電子 |
| 英文描述： | 16 V Quad Operational Amplifier |
| 中文描述： | QUAD OP-AMP, 15000 uV OFFSET-MAX, 5.8 MHz BAND WIDTH, PQCC16 |
| 封裝： | LEAD-FREE, MO-220-VGGC, LFCSP-16 |
| 文件頁數： | 12/16頁 |
| 文件大小： | 546K |
| 代理商： | ADD8704ACPZ-REEL7 |
ADD8704
APPLICATION INFORMATION
THEORY
The ADD8704 is designed for use in LCD gamma correction
circuits. Depending on the panel architecture, between 4 and 18
different gamma voltages may be needed. These gamma
voltages provide the reference voltages for the column driver
RDACs. Due to the capacitive nature of LCD panels, it is
necessary for these drivers to provide high capacitive load drive.
In addition to providing gamma reference voltages, these parts
are also capable of providing the V
COM
voltage. V
COM
is the
center voltage common to all the LCD pixels. Since the V
COM
circuit is common to all the pixels in the panel, the V
COM
driver
is designed to supply continuous currents up to 35 mA.
INPUT
The ADD8704 has four amplifiers specifically designed for the
needs of an LCD panel. F
correction curve for a normally white twisted nematic LCD
panel. The symmetric curve comes from the need to reverse the
polarity on the LC pixels to avoid “burning” in the image. The
application therefore requires gamma voltages that come close
to both supply rails. To accommodate this transfer function, the
ADD8704 has been designed to have four different amplifiers in
one package.
shows a typical gamma
igure 36
Figure 36. LCD Gamma Correction Curve
GRAY SCALE BITS
G
0
16
32
48
64
V
DD
V
G2
V
G3
V
G4
V
G1
V
G5
V
G6
V
G7
V
G8
V
G9
V
G10
V
SS
0
Amplifier A has a single-supply PNP input stage followed by a
folded cascode stage. This provides an input range that goes to
the bottom rail. This amplifier can therefore be used to provide
the bottom voltage on the RDAC string.
Amplifier B (PNP folded cascode) swings to the low rail as well,
but it provides 35 mA continuous output current versus 15 mA.
This buffer is suitable for lower RDAC range, middle RDAC
range, or V
COM
applications.
Amplifier C is a rail-to-rail input range that makes the
ADD8704 suitable for use anywhere on the RDAC as well as for
V
COM
applications.
Amplifier D has an NPN follower input stage. This covers the
upper rail to GND plus 1.7 V. This amplifier is suitable for the
upper range of the RDAC.
OUTPUT
The outputs of the amplifiers have been designed to match the
performance needs of the gamma correction circuit. All four of
the amplifiers have rail-to-rail outputs, but the current drive
capabilities differ. Since amplifier A is suited for voltages close
to V
SS
(GND), the output is designed to sink more current than
it sources; it can sink 15 mA of continuous current. Likewise,
since amplifier D is primarily used for voltages close to V
DD
, it
sources more current. Amplifier D can source 15 mA of
continuous current. Amplifiers B and C are designed for use as
either midrange gamma or V
COM
amplifiers. They therefore sink
and source equal amounts of current. Since they are used as
V
COM
amplifiers, they have a drive capability of up to 35 mA of
continuous current.
The nature of LCD panels introduces a large amount of
parasitic capacitance from the column drivers as well as the
capacitance associated with the liquid crystals via the common
plane. This makes capacitive drive capability an important
factor when designing the gamma correction circuit.
IMPORTANT NOTE
Because of the asymmetric nature of amplifiers A and D, care
must be taken to connect an input that forces the amplifiers to
operate in their most productive output states. Amplifier D has
very limited sink capabilities, while amplifier A does not source
well. If more than one ADD8704 is used, set the amplifier D
input to enable the amplifier output to source current and set
the amplifier A input to force a sinking output current. This
means making sure the input is above the midpoint of the
common-mode input range for amplifier D and below the
midpoint for amplifier A. Mathematically speaking, make sure
V
IN
> V
S
/2 for amplifier D and V
IN
< V
S
/2 for amplifier A.
Figure 37 shows an example using 4 ADD8704s to generate 10
gamma outputs. Note that the top three resistor tap-points are
connected to the amplifier D inputs, thus assuring these
channels will source current. Likewise, the bottom three resistor
tap-points are connected to the amplifier A inputs to provide
sinking output currents.
Rev. 0 | Page 12 of 16
相關PDF資料 |
PDF描述 |
|---|---|
| ADD8704ARU | 16 V Quad Operational Amplifier |
| ADD8704ARU-REEL | 16 V Quad Operational Amplifier |
| ADD8704ARUZ | 16 V Quad Operational Amplifier |
| ADD8704ARUZ-REEL | 16 V Quad Operational Amplifier |
| ADD8706 | 16 V 5 + 1-Channel Operational Amplifier |
相關代理商/技術參數 |
參數描述 |
|---|---|
| ADD8704ARU | 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:Analog Devices 功能描述: |
| ADD8704ARU-REEL | 制造商:Rochester Electronics LLC 功能描述:- Tape and Reel 制造商:Analog Devices 功能描述: |
| ADD8704ARUZ | 制造商:Analog Devices 功能描述:OP Amp Quad GP R-R O/P 16.5V 14-Pin TSSOP 制造商:Rochester Electronics LLC 功能描述: |
| ADD8704ARUZ-REEL | 功能描述:IC OPAMP LCD QUAD 16V 14-TSSOP RoHS:是 類別:集成電路 (IC) >> 線性 - 放大器 - 視頻放大器和頻緩沖器 系列:- 標準包裝:1,000 系列:- 應用:驅動器 輸出類型:差分 電路數:3 -3db帶寬:350MHz 轉換速率: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 安裝類型:表面貼裝 封裝/外殼:20-VFQFN 裸露焊盤 供應商設備封裝:20-QFN 裸露焊盤（4x4） 包裝:帶卷 (TR) |
| ADD8706 | 制造商:AD 制造商全稱:Analog Devices 功能描述:16 V 5 + 1-Channel Operational Amplifier |
發布緊急采購，3分鐘左右您將得到回復。