- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄375242 > AD8039AR-REEL (ANALOG DEVICES INC) Low Power 350 MHz Voltage Feedback Amplifiers PDF資料下載
參數(shù)資料
| 型號： | AD8039AR-REEL |
| 廠商： | ANALOG DEVICES INC |
| 元件分類： | 運(yùn)動控制電子 |
| 英文描述： | Low Power 350 MHz Voltage Feedback Amplifiers |
| 中文描述： | DUAL OP-AMP, 3000 uV OFFSET-MAX, PDSO8 |
| 封裝： | MS-012AA, SOIC-8 |
| 文件頁數(shù)： | 9/12頁 |
| 文件大?。?/td> | 346K |
| 代理商： | AD8039AR-REEL |
REV. B
AD8038/AD8039
–9–
FREQUENCY – MHz
I
–90
–80
–70
–60
–50
–40
–30
–20
–10
0
0.1
1000
1.0
10
100
TPC 37. AD8038 Input-Output Isolation (G = +2,
R
L
= 2 k
, V
S
=
±
5V
LAYOUT, GROUNDING, AND BYPASSING
CONSIDERATIONS
Disable
The AD8038 in the SOIC-8 package provides a disable feature.
This feature disables the input from the output (see TPC 37 for
input-output isolation) and reduces the quiescent current from
typically 1 mA to 0.2 mA. When the
DISABLE
node is pulled
below 4.5 V from the positive supply rail, the part becomes
disabled. In order to enable the part, the
DISABLE
node needs
to be pulled up to above 2.5 V below the positive rail.
Power Supply Bypassing
Power supply pins are actually inputs, and care must be taken
so that a noise-free stable dc voltage is applied. The purpose
of bypass capacitors is to create low impedances from the sup-
ply to ground at all frequencies, thereby shunting or filtering a
majority of the noise.
Decoupling schemes are designed to minimize the bypassing
impedance at all frequencies with a parallel combination of
capacitors. 0.01
μ
F or 0.001
μ
F (X7R or NPO) chip capacitors
are critical and should be as close as possible to the amplifier
package. Larger chip capacitors, such as the 0.1
μ
F capacitor,
can be shared among a few closely spaced active components in
the same signal path. A 10
μ
F tantalum capacitor is less critical
for high frequency bypassing and, in most cases, only one per
board is needed at the supply inputs.
Grounding
A ground plane layer is important in densely packed PC boards
to spread the current minimizing parasitic inductances.
However, an understanding of where the current flows in a circuit
is critical to implementing effective high speed circuit design.
The length of the current path is directly proportional to the
magnitude of parasitic inductances, and thus the high frequency
impedance of the path. High speed currents in an inductive
ground return will create an unwanted voltage noise.
The length of the high frequency bypass capacitor leads are most
critical. A parasitic inductance in the bypass grounding will
work against the low impedance created by the bypass capacitor.
Place the ground leads of the bypass capacitors at the same
physical location. Because load currents flow from the supplies
as well, the ground for the load impedance should be at the
same physical location as the bypass capacitor grounds. For the
larger value capacitors, which are intended to be effective at
lower frequencies, the current return path distance is less critical.
Input Capacitance
Along with bypassing and ground, high speed amplifiers can be
sensitive to parasitic capacitance between the inputs and ground. A
few pF of capacitance will reduce the input impedance at high
frequencies, in turn increasing the amplifiers’ gain, causing peaking
of the frequency response, or even oscillations if severe enough.
It is recommended that the external passive components that
are connected to the input pins be placed as close as possible to
the inputs to avoid parasitic capacitance. The ground and power
planes must be kept at a distance of at least 0.05 mm from the
input pins on all layers of the board.
Output Capacitance
To a lesser extent, parasitic capacitances on the output can cause
peaking of the frequency response. There are two methods to
minimize this effect.
1. Put a small value resistor in series with the output to isolate
the load capacitor from the amp’s output stage; see TPCs 7,
8, 22, and 23.
2. Increase the phase margin with higher noise gains or add a pole
with a parallel resistor and capacitor from –IN to the output.
Input-to-Output Coupling
The input and output signal traces should not be parallel to
minimize capacitive coupling between the inputs and outputs,
avoiding any positive feedback.
APPLICATIONS
Low Power ADC Driver
8
1
0.1 F
10 F
+5V
0.1 F
10 F
7
0.1 F
10 F
–5V
3
2
6
5
4
AD8039
1k
1k
1k
1k
VINA
VINB
REF
50
50
AD9203
1k
1k
1k
1k
V
IN
0V
3V
2.5V
Figure 3. Schematic to Drive AD9203 with the AD8039
Differential A/D Driver
The AD9203 is a low power (125 mW on a 5 V supply) 40 MSPS
10-bit converter. This represents a breakthrough in power/speed
for ADCs. As such, the low power, high performance AD8039
is an appropriate choice of amplifier to drive it.
In low supply voltage applications, differential analog inputs are
needed to increase the dynamic range of the ADC inputs.
Differential driving can also reduce second and other even-order
distortion products. The AD8039 can be used to make a
dc-coupled, single-ended-to-differential driver for one of these
ADCs. Figure 3 is a schematic of such a circuit for driving an
AD9203, a 10-bit, 40 MSPS ADC.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| AD8039AR-REEL7 | Low Power 350 MHz Voltage Feedback Amplifiers |
| AD8044ARZ-14 | Quad 150 MHz Rail-to-Rail Amplifier |
| AD8044ARZ-14-REEL | Quad 150 MHz Rail-to-Rail Amplifier |
| AD8044ARZ-14-REEL7 | Quad 150 MHz Rail-to-Rail Amplifier |
| AD805 | Data Retiming Phase-Locked Loop(重定時(shí)PLL) |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| AD8039AR-REEL7 | 功能描述:IC OPAMP VF DUAL LP LN 8SOIC RoHS:否 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標(biāo)準(zhǔn)包裝:1,000 系列:- 放大器類型:電壓反饋 電路數(shù):4 輸出類型:滿擺幅 轉(zhuǎn)換速率:33 V/µs 增益帶寬積:20MHz -3db帶寬:30MHz 電流 - 輸入偏壓:2nA 電壓 - 輸入偏移:3000µV 電流 - 電源:2.5mA 電流 - 輸出 / 通道:30mA 電壓 - 電源，單路/雙路(±):4.5 V ~ 16.5 V，±2.25 V ~ 8.25 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:14-SOIC（0.154"，3.90mm 寬） 供應(yīng)商設(shè)備封裝:14-SOIC 包裝:帶卷 (TR) |
| AD8039ART-EBZ | 功能描述:BOARD EVAL FOR AD8039ART RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 評估板 - 運(yùn)算放大器 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:1 系列:- |
| AD8039ART-R2 | 制造商:Analog Devices 功能描述: 制造商:Analog Devices 功能描述:IC,Operational Amplifier,DUAL,BIPOLAR,TSSOP,8PIN,PLASTIC |
| AD8039ART-REEL | 制造商:Analog Devices 功能描述:OP AMP DUAL VOLT FDBK 6V/12V 8PIN SOT-23 - Tape and Reel |
| AD8039ART-REEL7 | 功能描述:IC OPAMP VF DUAL LP LN SOT23-8 RoHS:否 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 放大器類型:通用 電路數(shù):1 輸出類型:滿擺幅 轉(zhuǎn)換速率:0.11 V/µs 增益帶寬積:350kHz -3db帶寬:- 電流 - 輸入偏壓:4nA 電壓 - 輸入偏移:20µV 電流 - 電源:260µA 電流 - 輸出 / 通道:20mA 電壓 - 電源，單路/雙路(±):2.7 V ~ 36 V，±1.35 V ~ 18 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-SOIC（0.154"，3.90mm 寬） 供應(yīng)商設(shè)備封裝:8-SO 包裝:帶卷 (TR) |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。