參數(shù)資料
型號(hào): AD8651ARMZ-R2
廠商: Analog Devices Inc
文件頁數(shù): 7/20頁
文件大?。?/td> 0K
描述: IC OPAMP VF CMOS 50MHZ LN 8MSOP
標(biāo)準(zhǔn)包裝: 1
系列: DigiTrim®
放大器類型: 電壓反饋
電路數(shù): 1
輸出類型: 滿擺幅
轉(zhuǎn)換速率: 41 V/µs
增益帶寬積: 50MHz
電流 - 輸入偏壓: 1pA
電壓 - 輸入偏移: 100µV
電流 - 電源: 9.5mA
電流 - 輸出 / 通道: 40mA
電壓 - 電源,單路/雙路(±): 2.7 V ~ 5.5 V,±1.35 V ~ 2.75 V
工作溫度: -40°C ~ 125°C
安裝類型: 表面貼裝
封裝/外殼: 8-TSSOP,8-MSOP(0.118",3.00mm 寬)
供應(yīng)商設(shè)備封裝: 8-MSOP
包裝: 標(biāo)準(zhǔn)包裝
其它名稱: AD8651ARMZ-R2DKR
Data Sheet
AD8651/AD8652
Rev. D | Page 15 of 20
Input Protection
As with any semiconductor device, if a condition exists for the
input voltage to exceed the power supply, the device input
overvoltage characteristic must be considered. The inputs of the
AD865x family are protected with ESD diodes to either power
supply. Excess input voltage energizes internal PN junctions in
the AD865x, allowing current to flow from the input to the
supplies. This results in an input stage with picoamps of input
current that can withstand up to 4000 V ESD events (human
body model) with no degradation.
Excessive power dissipation through the protection devices
destroys or degrades the performance of any amplifier. Differential
voltages greater than 7 V result in an input current of approximately
(| VCC – VEE | – 0.7 V)/RI, where RI is the resistance in series with
the inputs. For input voltages beyond the positive supply, the
input current is approximately (VIN – VCC – 0.7)/RI. For input
voltages beyond the negative supply, the input current is about
(VIN – VEE + 0.7)/RI. If the inputs of the amplifier sustain
differential voltages greater than 7 V or input voltages beyond
the amplifier power supply, limit the input current to 10 mA by
using an appropriately sized input resistor (RI), as shown in
(| VCC – VEE | – 0.7V)
30mA
FOR LARGE | VCC – VEE |
FOR VIN BEYOND
SUPPLY VOLTAGES
RI >
RI
– VIN +
+ VO
30mA
(VIN – VEE + 0.7V)
RI >
30mA
(VIN – VEE – 0.7V)
RI >
+
AD865x
03301-
054
Figure 55. Input Protection Method
Overdrive Recovery
Overdrive recovery is defined as the time it takes for the output
of an amplifier to come off the supply rail after an overload signal is
initiated. This is usually tested by placing the amplifier in a closed-
loop gain of 15 with an input square wave of 200 mV p-p while the
amplifier is powered from either 5 V or 3 V. The AD865x family
has excellent recovery time from overload conditions (see Figure 31
and Figure 32). The output recovers from the positive supply rail
within 200 ns at all supply voltages. Recovery from the negative rail
is within 100 ns at 5 V supply.
LAYOUT, GROUNDING, AND BYPASSING
CONSIDERATIONS
Power Supply Bypassing
Power supply pins can act as inputs for noise, so care must be
taken that a noise-free, stable dc voltage is applied. The purpose
of bypass capacitors is to create low impedances from the supply
to ground at all frequencies, thereby shunting or filtering most
of the noise.
Bypassing schemes are designed to minimize the supply
impedance at all frequencies with a parallel combination of
capacitors of 0.1 F and 4.7 F. Chip capacitors of 0.1 F (X7R
or NPO) are critical and should be as close as possible to the
amplifier package. The 4.7 F tantalum capacitor is less critical
for high frequency bypassing, and, in most cases, only one is
needed per board at the supply inputs.
Grounding
A ground plane layer is important for 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, therefore, the high
frequency impedance of the path. High speed currents in an
inductive ground return create an unwanted voltage noise.
The length of the high frequency bypass capacitor leads is
critical. A parasitic inductance in the bypass grounding works
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 also flow from the
supplies, the ground for the load impedance should be at the
same physical location as the bypass capacitor grounds. For the
larger value capacitors, intended to be effective at lower
frequencies, the current return path distance is less critical.
Leakage Currents
Poor PC board layout, contaminants, and the board insulator
material can create leakage currents that are much larger than the
input bias current of the AD865x family. Any voltage differential
between the inputs and nearby traces sets up leakage currents
through the PC board insulator, for example 1 V/100 G = 10 pA.
Similarly, any contaminants on the board can create significant
leakage (skin oils are a common problem).
To significantly reduce leakages, put a guard ring (shield)
around the inputs and the input leads that are driven to the
same voltage potential as the inputs. This ensures that there is
no voltage potential between the inputs and the surrounding
area to set up any leakage currents. To be effective, the guard
ring must be driven by a relatively low impedance source and
should completely surround the input leads on all sides, above
and below, using a multilayer board.
Another effect that can cause leakage currents is the charge
absorption of the insulator material itself. Minimizing the
amount of material between the input leads and the guard
ring helps to reduce the absorption. Also, low absorption
materials, such as Teflon or ceramic, may be necessary in
some instances.
相關(guān)PDF資料
PDF描述
0001.2516.PT FUSE 16A 250V 5X20 T-LAG CERM
RGH1608-2C-P-911-B RES 910 OHM 1/6W 0.1% 0603 SMD
0001.2508.PT FUSE 2.5A 250V 5X20 T-LAG CERM
RGH1608-2C-P-821-B RES 820 OHM 1/6W 0.1% 0603 SMD
0001.2514.PT FUSE 10A 250V 5X20 T-LAG CERM
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD8651ARMZ-R21 制造商:AD 制造商全稱:Analog Devices 功能描述:50 MHz, Precision, Low Distortion, Low Noise CMOS Amplifiers
AD8651ARMZ-REEL 功能描述:IC OPAMP VF CMOS 50MHZ LN 8MSOP RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:DigiTrim® 產(chǎn)品培訓(xùn)模塊:Differential Circuit Design Techniques for Communication Applications 標(biāo)準(zhǔn)包裝:1 系列:- 放大器類型:RF/IF 差分 電路數(shù):1 輸出類型:差分 轉(zhuǎn)換速率:9800 V/µs 增益帶寬積:- -3db帶寬:2.9GHz 電流 - 輸入偏壓:3µA 電壓 - 輸入偏移:- 電流 - 電源:40mA 電流 - 輸出 / 通道:- 電壓 - 電源,單路/雙路(±):3 V ~ 3.6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:16-VQFN 裸露焊盤,CSP 供應(yīng)商設(shè)備封裝:16-LFCSP-VQ 包裝:剪切帶 (CT) 產(chǎn)品目錄頁面:551 (CN2011-ZH PDF) 其它名稱:ADL5561ACPZ-R7CT
AD8651ARMZ-REEL1 制造商:AD 制造商全稱:Analog Devices 功能描述:50 MHz, Precision, Low Distortion, Low Noise CMOS Amplifiers
AD8651AR-REEL 制造商:Analog Devices 功能描述:OP Amp Single GP R-R I/O 5.5V 8-Pin SOIC N T/R
AD8651AR-REEL7 制造商:Analog Devices 功能描述:OP Amp Single GP R-R I/O 5.5V 8-Pin SOIC N T/R