使用自动调零放大器进行全桥放大以降低输入参考噪声

This circuit shows an example of a simple amplification scheme. This example produces a differential output with a common mode voltage of 2.5V, as determined by the bridge. The use of a true three amplifier instrumentation amplifier is not necessary, as the LTC2430/LTC2431 have common mode  rejection far beyond that of most amplifiers. The LTC1051 is a dual autozero amplifier that can be used to produce a gain of 10 before its input referred noise dominates the LTC2430/LTC2431 noise. This example shows a gain of 34, that is determined by a feedback network built using a resistor array containing eight individual resistors. The resistors are organized to optimize temperature tracking in the presence of thermal gradients. The second LTC1051 buffers the low noise input stage from the transient load steps produced during conversion.