参数资料
型号: MAX4257ESA+T
厂商: Maxim Integrated Products
文件页数: 3/16页
文件大小: 0K
描述: IC OP AMP R-R LN 8-SOIC
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 2,500
放大器类型: 通用
电路数: 2
输出类型: 推挽式,满摆幅
转换速率: 2.1 V/µs
增益带宽积: 22MHz
电流 - 输入偏压: 1pA
电压 - 输入偏移: 70µV
电流 - 电源: 420µA
电流 - 输出 / 通道: 68mA
电压 - 电源,单路/双路(±): 2.4 V ~ 5.5 V,±1.2 V ~ 2.75 V
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 8-SOIC(0.154",3.90mm 宽)
供应商设备封装: 8-SOIC
包装: 带卷 (TR)
UCSP, Single-Supply, Low-Noise,
Low-Distortion, Rail-to-Rail Op Amps
Maxim Integrated
11
MAX4249–MAX4257
Using a Feed-Forward Compensation
Capacitor, CZ
The amplifier’s input capacitance is 11pF. If the resis-
tance seen by the inverting input is large (feedback
network), this can introduce a pole within the amplifier’s
bandwidth, resulting in reduced phase margin.
Compensate the reduced phase margin by introducing
a feed-forward capacitor (CZ) between the inverting
input and the output (Figure 1). This effectively cancels
the pole from the inverting input of the amplifier.
Choose the value of CZ as follows:
CZ = 11 x (RF / RG) [pF]
In the unity-gain stable MAX4250–MAX4254, the use of
a proper CZ is most important for AV = 2V/V, and
AV = -1V/V. In the decompensated MAX4249/
MAX4255/MAX4256/MAX4257, CZ is most important
for AV = 10V/V. Figures 2a and 2b show transient
response both with and without CZ.
Using a slightly smaller CZ than suggested by the for-
mula above achieves a higher bandwidth at the
expense of reduced phase and gain margin. As a gen-
eral guideline, consider using CZ for cases where RG ||
RF is greater than 20k" (MAX4250–MAX4254) or
greater than 5k" (MAX4249/MAX4255/MAX4256/
MAX4257).
Applications Information
The MAX4249–MAX4257 combine good driving capa-
bility with ground-sensing input and rail-to-rail output
operation. With their low distortion, low noise, and low-
power consumption, these devices are ideal for use in
portable instrumentation systems and other low-power,
noise-sensitive applications.
Ground-Sensing and Rail-to-Rail Outputs
The common-mode input range of these devices
extends below ground, and offers excellent common-
mode rejection. These devices are guaranteed not to
undergo phase reversal when the input is overdriven
(Figure 3).
Figure 4 showcases the true rail-to-rail output opera-
tion of the amplifier, configured with AV = 10V/V. The
output swings to within 8mV of the supplies with a
10k" load, making the devices ideal in low-supply-
voltage applications.
Output Loading and Stability
Even with their low quiescent current of 400A, these
amplifiers can drive 1k" loads while maintaining excel-
lent DC accuracy. Stability while driving heavy capaci-
tive loads is another key feature.
VOUT
VIN
RISO
CL
MAX4250
MAX4251
MAX4252
MAX4253
MAX4254
4.25V
4.45V
-200mV
0
VOUT
VIN
AV = 1
VDD = 5V
RL = 10kΩ
20
s/div
0
5V
VDD = 5V
RL = 10kΩ
AV = 10
f = 1kHz
200
s/div
VOUT
1V/div
Figure 3. Overdriven Input Showing No Phase Reversal
Figure 4. Rail-to-Rail Output Operation
Figure 5. Capacitive-Load Driving Circuit
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相关代理商/技术参数
参数描述
MAX4257EUA 功能描述:运算放大器 - 运放 Low-Distortion Rail-Rail Op Amp RoHS:否 制造商:STMicroelectronics 通道数量:4 共模抑制比(最小值):63 dB 输入补偿电压:1 mV 输入偏流(最大值):10 pA 工作电源电压:2.7 V to 5.5 V 安装风格:SMD/SMT 封装 / 箱体:QFN-16 转换速度:0.89 V/us 关闭:No 输出电流:55 mA 最大工作温度:+ 125 C 封装:Reel
MAX4257EUA+ 功能描述:运算放大器 - 运放 Low-Distortion Rail-Rail Op Amp RoHS:否 制造商:STMicroelectronics 通道数量:4 共模抑制比(最小值):63 dB 输入补偿电压:1 mV 输入偏流(最大值):10 pA 工作电源电压:2.7 V to 5.5 V 安装风格:SMD/SMT 封装 / 箱体:QFN-16 转换速度:0.89 V/us 关闭:No 输出电流:55 mA 最大工作温度:+ 125 C 封装:Reel
MAX4257EUA+T 功能描述:运算放大器 - 运放 Low-Distortion Rail-Rail Op Amp RoHS:否 制造商:STMicroelectronics 通道数量:4 共模抑制比(最小值):63 dB 输入补偿电压:1 mV 输入偏流(最大值):10 pA 工作电源电压:2.7 V to 5.5 V 安装风格:SMD/SMT 封装 / 箱体:QFN-16 转换速度:0.89 V/us 关闭:No 输出电流:55 mA 最大工作温度:+ 125 C 封装:Reel
MAX4257EUA-T 功能描述:运算放大器 - 运放 Low-Distortion Rail-Rail Op Amp RoHS:否 制造商:STMicroelectronics 通道数量:4 共模抑制比(最小值):63 dB 输入补偿电压:1 mV 输入偏流(最大值):10 pA 工作电源电压:2.7 V to 5.5 V 安装风格:SMD/SMT 封装 / 箱体:QFN-16 转换速度:0.89 V/us 关闭:No 输出电流:55 mA 最大工作温度:+ 125 C 封装:Reel
MAX4258ESA 功能描述:视频放大器 Integrated Circuits (ICs) RoHS:否 制造商:ON Semiconductor 通道数量:4 电源类型: 工作电源电压:3.3 V, 5 V 电源电流: 最小工作温度: 最大工作温度: 封装 / 箱体:TSSOP-14 封装:Reel