ns lmp8100a可编增益放大器利用软件调节增益，增益则由1v/v至16v/v，共分为16个步级, 以1v/v作为一步级增减, 在摄氏-40度至 125度的工业温度范围内操作, 增益准确度保证可达0.03%,而在摄氏-40度至 85度的温度范围内操作，增益准确度保证可达0.075%。lmp8100!可编程增益放大器的核心，具有33mhz cmos 输入、轨到轨输入/输出（rrio）运算放大器、典型的110db开环增益等特征,非常适用于工业设备及测量仪表等产品.本文提供了lmp8100的主要特性,方框图以及测试电路和应用电路图.

lmp8100a的可编程增益放大器利用软件调节增益，增益则由1v/v至16v/v，共分为16个步级，以1v/v作为一步级增减，而且在摄氏-40度至 125度的工业温度范围内操作，增益准确度保证可达0.03%。此外，美国国家半导体也推出型号为lmp8100的半高精度级别可编程增益放大器，其特点是只要在摄氏-40度至 85度的温度范围内操作，增益准确度保证可达0.075%。这两款放大器的闭环增益可以通过一列共16个高精度薄膜电阻加以设定。这两款可编程增益放大器的核心，都具有33mhz cmos 输入、轨到轨输入/输出（rrio）运算放大器、典型的110db开环增益等特征、。适用于工业设备及测量仪表等产品
lmp8100a芯片可提供四种级别的内部频率补偿，因此即使采用较高的增益比率，可供使用的信号带宽也会随着增加。这款芯片设有输入零校准功能，可让用户测量输出偏移电压，以便校准因温度或电压漂移而产生的任何误差。此外，这款放大器的控制模式可以通过串行端口加以设定，甚至几颗芯片也可以通过这一串行端口串联一起，这样一列多颗lmp8100放大器可以利用微控制器的串行数据流加以设定。这款芯片的控制模式寄存器采用两个缓冲区，确保不同设定之间的变换不会出现信号跳变。

lmp8100a芯片的压摆率为12v/us，而单位增益带宽为33mhz。这款芯片适用于2.7v至5.5v之间的供电电压，若供电电流为5.3ma，可以输出20ma的电流。如果采用停机模式，耗电量可降低至20ua。

lmp8100a及lmp8100两款芯片都采用美国国家半导体专有的vip50 bicmos 放大器系列的最新型号产品。这系列放大器可以大幅提高系统的精度，并降低功耗。工艺技术制造，是该公司的高精度、低电压及低功率lmp



lmp8100 programmable gain amplifier

概述:

the lmp8100 programmable gain amplifier features an adjustable gain from 1 to 16 v/v in 1 v/v increments. at the core of the lmp8100 is a precision, 33 mhz, cmos input, rail-torail input/output operational amplifier with a typical open-loop gain of 110 db. amplifier closed-loop gain is set by an array of precision thin-film resistors. amplifier control modes are programmed via a serial port that allows devices to be cascaded so that an array of lmp8100 amplifiers can be programmed by a single serial data stream. the control mode registers are double buffered to insure glitch-free transitions between programmed settings. the lmp8100 is part of the lmpprecision amplifier family and is ideal for a variety of applications.

the amplifier features several programmable controls including: gain; a power-conserving shutdown mode which can reduce current consumption to only 20 μa; an input zeroing switch which allows the output offset voltage to be measured to facilitate system calibration; and four levels of internal frequency compensation which can be set to maximize bandwidth at the different gain settings.

the lmp8100 comes in a 14-pin soic package.

特性:
typical values, ta = 25°c
■ gain error (over temperature range)
— lmp8100a 0.03%
— lmp8100 0.075%
■ gain range 1 to 16 v/v in 1 v/v steps
■ programmable frequency compensation
■ input zero calibration switch
■ input offset voltage (max, lmp8100a) 250 μv
■ input bias current 0.1 pa
■ input noise voltage 12 nv/√hz
■ unity gain bandwidth 33 mhz
■ slew rate 12 v/μs
■ output current 20 ma
■ supply voltage range 2.7v to 5.5v
■ supply current 5.3 ma
■ rail-to-rail output swing v+ −50 mv to v− +50 mv

应用:
■ industrial instrumentation
■ data acquisition systems
■ test equipment
■ scaling amplifier
■ gain control
■ sensor interface