參數(shù)資料
型號: AD812ANZ
廠商: Analog Devices Inc
文件頁數(shù): 5/16頁
文件大?。?/td> 0K
描述: IC OPAMP DUAL CURR-FDBK 8-DIP
標準包裝: 50
應用: 電流反饋
電路數(shù): 2
-3db帶寬: 145MHz
轉換速率: 1600 V/µs
電流 - 電源: 4.5mA
電流 - 輸出 / 通道: 50mA
電壓 - 電源,單路/雙路(±): 2.4 V ~ 36 V,±1.2 V ~ 18 V
安裝類型: 通孔
封裝/外殼: 8-DIP(0.300",7.62mm)
供應商設備封裝: 8-PDIP
包裝: 管件
產品目錄頁面: 768 (CN2011-ZH PDF)
AD812
–13–
REV. B
Power Supply Bypassing
Adequate power supply bypassing can be very important when
optimizing the performance of high speed circuits. Inductance
in the supply leads can (for example) contribute to resonant
circuits that produce peaking in the amplifier’s response. In
addition, if large current transients must be delivered to a load,
then large (greater than 1
F) bypass capacitors are required to
produce the best settling time and lowest distortion. Although
0.1
F capacitors may be adequate in some applications, more
elaborate bypassing is required in other cases.
When multiple bypass capacitors are connected in parallel, it is
important to be sure that the capacitors themselves do not form
resonant circuits. A small (say 5
) resistor may be required in
series with one of the capacitors to minimize this possibility.
As discussed below, power supply bypassing can have a signifi-
cant impact on crosstalk performance.
Achieving Low Crosstalk
Measured crosstalk from the output of amplifier 2 to the input
of amplifier 1 of the AD812 is shown in Figure 40. The crosstalk
from the output of amplifier 1 to the input of amplifier 2 is a few
dB better than this due to the additional distance between criti-
cal signal nodes.
A carefully laid-out PC board should be able to achieve the level
of crosstalk shown in the figure. The most significant contribu-
tors to difficulty in achieving low crosstalk are inadequate power
supply bypassing, overlapped input and/or output signal paths,
and capacitive coupling between critical nodes.
The bypass capacitors must be connected to the ground plane at
a point close to and between the ground reference points for the
two loads. (The bypass of the negative power supply is particu-
larly important in this regard.) There are two amplifiers in the
package, and low impedance signal return paths must be pro-
vided for each load. (Using a parallel combination of 1
F,
0.1
F, and 0.01 F bypass capacitors will help to achieve opti-
mal crosstalk.)
–10
–60
–110
1M
100M
10M
–70
–80
–90
–100
–50
–40
–30
–20
CROSSTALK
dB
100k
FREQUENCY – Hz
RL = 150
Figure 40. Crosstalk vs. Frequency
The input and output signal return paths must also be kept from
overlapping. Since ground connections are not of perfectly zero
impedance, current in one ground return path can produce a
voltage drop in another ground return path if they are allowed
to overlap.
Electric field coupling external to (and across) the package can
be reduced by arranging for a narrow strip of ground plane to be
run between the pins (parallel to the pin rows). Doing this on
both sides of the board can reduce the high frequency crosstalk
by about 5 dB or 6 dB.
Driving Capacitive Loads
When used with the appropriate output series resistor, any load
capacitance can be driven without peaking or oscillation. In
most cases, less than 50
is all that is needed to achieve an
extremely flat frequency response. As illustrated in Figure 44,
the AD812 can be very attractive for driving largely capacitive
loads. In this case, the AD812’s high output short circuit
current allows for a 150 V/
s slew rate when driving a 510 pF
capacitor.
AD812
8
4
RG
RF
VIN
RT
VO
RL
CL
RS
+VS
0.1 F
1.0 F
0.1 F
1.0 F
–VS
Figure 41. Circuit for Driving a Capacitive Load
1
10
1000
100
FREQUENCY – MHz
6
9
3
0
–3
CLOSED-LOOP
GAIN
dB
12
–6
VS = 5V
G = +2
RF = 750
RL = 1k
CL = 10pF
RS = 0
RS = 30
RS = 50
Figure 42. Response to a Small Load Capacitor at
±5 V
相關PDF資料
PDF描述
AD812ARZ IC OPAMP DUAL CURR-FDBK 8-SOIC
AD810ARZ IC CURR-FDBK AMP VIDEO LP 8-SOIC
AD830ARZ IC VIDEO DIFF AMP HS 8-SOIC
VE-B64-MY-B1 CONVERTER MOD DC/DC 48V 50W
AD828ARZ IC VIDEO OPAMP DUAL LP 8-SOIC
相關代理商/技術參數(shù)
參數(shù)描述
AD812AR 功能描述:IC OPAMP DUAL CURR-FDBK 8-SOIC RoHS:否 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(shù):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)
AD812AR-8 制造商:Analog Devices 功能描述:
AD812AR-EBZ 功能描述:BOARD EVAL FOR AD812AR RoHS:是 類別:編程器,開發(fā)系統(tǒng) >> 評估演示板和套件 系列:* 標準包裝:1 系列:- 主要目的:電信,線路接口單元(LIU) 嵌入式:- 已用 IC / 零件:IDT82V2081 主要屬性:T1/J1/E1 LIU 次要屬性:- 已供物品:板,電源,線纜,CD 其它名稱:82EBV2081
AD812AR-REEL 功能描述:IC OPAMP DUAL CURR-FDBK 8-SOIC RoHS:否 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(shù):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)
AD812AR-REEL7 功能描述:IC OPAMP DUAL CURR-FDBK 8-SOIC RoHS:否 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(shù):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)