参数资料
型号: ADA4927-2YCPZ-RL
厂商: Analog Devices Inc
文件页数: 9/24页
文件大小: 0K
描述: IC OPAMP CF DIFF DUAL LN 24LFCSP
标准包装: 5,000
放大器类型: 电流反馈
电路数: 2
输出类型: 差分
转换速率: 5000 V/µs
-3db带宽: 2.3GHz
电流 - 输入偏压: 500nA
电压 - 输入偏移: 300µV
电流 - 电源: 20mA
电流 - 输出 / 通道: 65mA
电压 - 电源,单路/双路(±): 4.5 V ~ 11 V,±2.25 V ~ 5.5 V
工作温度: -40°C ~ 105°C
安装类型: 表面贴装
封装/外壳: 24-VFQFN 裸露焊盘,CSP
供应商设备封装: 24-LFCSP-VQ(4x4)
包装: 带卷 (TR)
ADA4927-1/ADA4927-2
Rev. A | Page 17 of 24
APPLICATIONS INFORMATION
ANALYZING AN APPLICATION CIRCUIT
The ADA4927 uses high open-loop transimpedance and negative
current feedback to control its differential output voltage in
such a way as to minimize the differential error currents. The
differential error currents are defined as the currents that flow
in and out of the differential inputs labeled +IN and IN (see
Figure 46). For most purposes, these currents can be assumed
to be zero. The voltage between the +IN and IN inputs is
internally bootstrapped to 0 V; therefore, the voltages at the
amplifier inputs are equal, and external analysis can be carried
out in a similar fashion to that of voltage feedback amplifiers.
Similarly, the difference between the actual output common-
mode voltage and the voltage applied to VOCM can also be assumed
to be zero. Starting from these principles, any application circuit
can be analyzed.
SETTING THE CLOSED-LOOP GAIN
Using the approach previously described, the differential gain of
the circuit in Figure 46 can be determined by
G
F
dm
IN
R
V
=
,
dm
OUT
R
V
,
This presumes that the input resistors (RG) and feedback
resistors (RF) on each side are of equal value.
ESTIMATING THE OUTPUT NOISE VOLTAGE
The differential output noise of the ADA4927 can be estimated
using the noise model in Figure 47. The input-referred noise
voltage density, vnIN, is modeled as a differential input, and the
noise currents, inIN and inIN+, appear between each input and
ground. The output voltage due to vnIN is obtained by multiplying
vnIN by the noise gain, GN (defined in the GN equation). The
noise currents are uncorrelated with the same mean-square value,
and each produces an output voltage that is equal to the noise
current multiplied by the associated feedback resistance. The
noise voltage density at the VOCM pin is vnCM. When the feedback
networks have the same feedback factor, as in most cases, the
output noise due to vnCM is common mode. Each of the four
resistors contributes (4kTRxx)1/2. The noise from the feedback
resistors appears directly at the output, and the noise from each
gain resistor appears at the output multiplied by RF/RG. Table 11
summarizes the input noise sources, the multiplication factors,
and the output-referred noise density terms.
V
ADA4927
+
RF2
VnOD
VnCM
VOCM
VnIN
RF1
RG2
RG1
nRF1
nRG1
VnRF2
inIN+
inIN–
07
57
4-
0
47
VnRG2
Figure 47. Noise Model
Table 11. Output Noise Voltage Density Calculations for Matched Feedback Networks
Input Noise Contribution
Input Noise Term
Input Noise
Voltage Density
Output
Multiplication Factor
Differential Output Noise
Voltage Density Term
Differential Input
vnIN
GN
vnO1 = GN(vnIN)
Inverting Input
inIN
inIN × (RF2)
1
vnO2 = (inIN)(RF2)
Noninverting Input
inIN
inIN × (RF1)
1
vnO3 = (inIN)(RF1)
VOCM Input
vnCM
0
vnO4 = 0
Gain Resistor, RG1
vnRG1
(4kTRG1)1/2
RF1/RG1
vnO5 = (RF1/RG1)(4kTRG1)1/2
Gain Resistor, RG2
vnRG2
(4kTRG2)1/2
RF2/RG2
vnO6 = (RF2/RG2)(4kTRG2)1/2
Feedback Resistor, RF1
vnRF1
(4kTRF1)1/2
1
vnO7 = (4kTRF1)1/2
Feedback Resistor, RF2
vnRF2
(4kTRF2)1/2
1
vnO8 = (4kTRF2)1/2
相关PDF资料
PDF描述
ADA4927-2YCPZ-R7 IC OPAMP CF DIFF DUAL LN 24LFCSP
76382-414LF CONN HEADER 14POS .100" R/A TIN
170823-8 CONN INSULATION SLEEVE .110
735075-1 CONN RCPT HSG .250 1POS RED
MCP631T-E/OT IC OP AMP SGL 24MHZ SOT23-5
相关代理商/技术参数
参数描述
ADA4930-1 制造商:AD 制造商全称:Analog Devices 功能描述:Ultralow Noise Drivers for Low Voltage ADCs
ADA4930-1SCPZ-EPR2 制造商:Analog Devices 功能描述:ULTRALOW DIST LOW VLTG ADC DRIVER - Tape and Reel 制造商:Analog Devices 功能描述:Differential Amplifiers UltraLow Dist Low Vltg ADC Driver
ADA4930-1SCPZ-EPR7 制造商:Analog Devices 功能描述:ULTRALOW DIST LOW VLTG ADC DRIVER - Tape and Reel 制造商:Analog Devices 功能描述:IC OPAMP DIFF 1.35GHZ 16LFCSP
ADA4930-1SCPZ-EPRL 制造商:Analog Devices 功能描述:ULTRALOW DIST LOW VLTG ADC DRIVER - Tape and Reel 制造商:Analog Devices 功能描述:IC OPAMP DIFF 1.35GHZ 16LFCSP 制造商:Analog Devices 功能描述:UltraLow Dist Low Vltg ADC Driver
ADA4930-1YCP-EBZ 功能描述:BOARD EVAL FOR ADA4930-1YCP RoHS:是 类别:编程器,开发系统 >> 评估板 - 运算放大器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:1 系列:-