参数资料
型号: AD823AR-REEL
厂商: ANALOG DEVICES INC
元件分类: 运动控制电子
英文描述: RECTIFIER SCHOTTKY SINGLE 8A 30V 200A-ifsm 0.55V-vf 0.5mA-ir TO220AC 50/TUBE
中文描述: DUAL OP-AMP, 3500 uV OFFSET-MAX, PDSO8
封装: PLASTIC, MS-012AA, SOIC-8
文件页数: 13/16页
文件大小: 439K
代理商: AD823AR-REEL
AD823
REV. 0
–13–
Since the input stage uses n-channel JFETs, input current dur-
ing normal operation is negative; the current flows out from the
input terminals. If the input voltage is driven more positive than
+V
S
– 0.4 V, the input current will reverse direction as internal
device junctions become forward biased. This is illustrated in
Figure 6.
A current limiting resistor should be used in series with the in-
put of the AD823 if there is a possibility of the input voltage ex-
ceeding the positive supply by more than 300 mV, or if an input
voltage will be applied to the AD823 when
±
V
S
= 0. The ampli-
fier will be damaged if left in that condition for more than 10
seconds. A 1 k
resistor allows the amplifier to withstand up to
10 volts of continuous overvoltage, and increases the input volt-
age noise by a negligible amount.
Input voltages less than –V
S
are a completely different story.
The amplifier can safely withstand input voltages 20 volts below
the minus supply voltage as long as the total voltage from the
positive supply to the input terminal is less than 36 volts. In
addition, the input stage typically maintains picoamp level input
currents across that input voltage range.
The AD823 is designed for 16 nV/
Hz
wideband input voltage
noise and maintains low noise performance to low frequencies
(refer to Figure 15). This noise performance, along with the
AD823’s low input current and current noise means that the
AD823 contributes negligible noise for applications with source
resistances greater than 10 k
and signal bandwidths greater
than 1 kHz.
OUTPUT CHARACTERISTICS
The AD823’s unique bipolar rail-to-rail output stage swings
within 25 mV of the supplies with no external resistive load. The
AD823’s approximate output saturation resistance is 25
sourcing and sinking. This can be used to estimate output satu-
ration voltage when driving heavier current loads. For instance,
when driving 5 mA, the saturation voltage to the rails will be ap-
proximately 125 mV.
If the AD823’s output is driven hard against the output satura-
tion voltage, it will recover within 250 ns of the input returning
to the amplifier’s linear operating region.
A/D Driver
The rail-to-rail output of the AD823 makes it useful as an A/D
driver in a single supply system. Because it is a dual op amp, it
can be used to drive both the analog input of the A/D along with
its reference input. The high impedance FET input of the
AD823 is well suited for minimally loading of high output im-
pedance devices.
Figure 38 shows a schematic of an AD823 being used to drive
both the input and reference input of an AD1672, a 12-bit
3 MSPS single supply A/D converter. One amplifier is config-
ured as a unity gain follower to drive the analog input of the
AD1672 which is configured to accept an input voltage that
ranges from 0 to 2.5 V.
13
14
12
11
10
9
8
7
6
5
4
3
2
1
19
18
+5VA
10μF
0.1μF
2
3
5
6
4
7
1
8
49.9
10μF
0.1
μF
0.1
μF
10
μF
0.1μF
+5VA
+5VD
+5VD
20
21
22
23
24
25
26
27
16
CLOCK
1k
1k
V
IN
V
(1.25V)
BIT1 (MSB)
BIT2
BIT3
BIT4
BIT5
BIT6
BIT7
BIT8
BIT9
BIT10
BIT11
BIT12 (LSB)
15
OTR
REFOUT
AIN1
AIN2
REFIN
IN COM
NCOMP2
NCOMP1
ACOM
COM
REF
D
COM
AD823
+V
CC
+V
DD
28
19
AD1672
Figure 38. AD823 Driving Input and Reference of the
AD1672, a 12-Bit 3 MSPS A/D Converter
The other amplifier is configured as a gain of two to drive the
reference input from a 1.25 V reference. Although the AD1672
has its own internal reference, there are systems that require
greater accuracy than the internal reference provides. On the
other hand, if the AD1672 internal reference is used, the second
AD823 amplifier can be used to buffer the reference voltage for
driving other circuitry while minimally loading the reference
source.
The circuit was tested with a 500 kHz sine wave input that was
heavily low pass filtered (60 dB) to minimize the harmonic con-
tent at the input to the AD823. The digital output of the
AD1672 was analyzed by performing an FFT.
During the testing, it was observed that at 500 kHz, the output
of the AD823 cannot go below about 350 mV (operating with
negative supply at ground) without seriously degrading the sec-
ond harmonic distortion. Another test was performed with a
200
pull-down resistor to ground that allowed the output to
go as low as 200 mV without seriously affecting the second har-
monic distortion. There was, however, a slight increase in the
third harmonic term with the resistor added, but it was still less
than the second harmonic.
相关PDF资料
PDF描述
AD824AN-3V VARISTOR 30VRMS 1206 SMD
AD824 Single Supply, Rail-to-Rail Low Power, FET-Input Op Amp
AD824AN Single Supply, Rail-to-Rail Low Power, FET-Input Op Amp
AD824AR Single Supply, Rail-to-Rail Low Power, FET-Input Op Amp
AD824BN Single Supply, Rail-to-Rail Low Power, FET-Input Op Amp
相关代理商/技术参数
参数描述
AD823AR-REEL7 功能描述:IC OPAMP JFET R-R DUAL LN 8SOIC RoHS:否 类别:集成电路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 标准包装:73 系列:Over-The-Top® 放大器类型:通用 电路数:4 输出类型:满摆幅 转换速率:0.07 V/µs 增益带宽积:200kHz -3db带宽:- 电流 - 输入偏压:1nA 电压 - 输入偏移:285µV 电流 - 电源:50µA 电流 - 输出 / 通道:25mA 电压 - 电源,单路/双路(±):2 V ~ 44 V,±1 V ~ 22 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:16-WFDFN 裸露焊盘 供应商设备封装:16-DFN-EP(5x3) 包装:管件
AD823ARZ 功能描述:IC OPAMP JFET R-R DUAL LN 8SOIC RoHS:是 类别:集成电路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 标准包装:2,500 系列:- 放大器类型:通用 电路数:4 输出类型:- 转换速率:0.6 V/µs 增益带宽积:1MHz -3db带宽:- 电流 - 输入偏压:45nA 电压 - 输入偏移:2000µV 电流 - 电源:1.4mA 电流 - 输出 / 通道:40mA 电压 - 电源,单路/双路(±):3 V ~ 32 V,±1.5 V ~ 16 V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:14-TSSOP(0.173",4.40mm 宽) 供应商设备封装:14-TSSOP 包装:带卷 (TR) 其它名称:LM324ADTBR2G-NDLM324ADTBR2GOSTR
AD823ARZ 制造商:Analog Devices 功能描述:Operational Amplifier (Op-Amp) IC
AD823ARZ-R7 功能描述:IC OPAMP JFET R-R DUAL LN 8SOIC RoHS:是 类别:集成电路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 标准包装:1 系列:- 放大器类型:通用 电路数:4 输出类型:满摆幅 转换速率:0.028 V/µs 增益带宽积:105kHz -3db带宽:- 电流 - 输入偏压:3nA 电压 - 输入偏移:100µV 电流 - 电源:3.3µA 电流 - 输出 / 通道:12mA 电压 - 电源,单路/双路(±):2.7 V ~ 12 V,±1.35 V ~ 6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:14-TSSOP(0.173",4.40mm 宽) 供应商设备封装:14-TSSOP 包装:剪切带 (CT) 其它名称:OP481GRUZ-REELCT
AD823ARZ-RL 功能描述:IC OPAMP JFET R-R DUAL LN 8SOIC RoHS:是 类别:集成电路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 标准包装:1 系列:- 放大器类型:通用 电路数:4 输出类型:满摆幅 转换速率:0.028 V/µs 增益带宽积:105kHz -3db带宽:- 电流 - 输入偏压:3nA 电压 - 输入偏移:100µV 电流 - 电源:3.3µA 电流 - 输出 / 通道:12mA 电压 - 电源,单路/双路(±):2.7 V ~ 12 V,±1.35 V ~ 6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:14-TSSOP(0.173",4.40mm 宽) 供应商设备封装:14-TSSOP 包装:剪切带 (CT) 其它名称:OP481GRUZ-REELCT