That THAT1570高性能电流反馈放大方案
That 公司的THAT1570是多用途高性能电流反馈放大器,适合用于差分麦克风前置放大器和总线加法应用.增益调整采用三个外接电阻来实现,范围从0到60dB. 工作电压±5V 到±18V,工作电流7.5mA,60 dB增益的输入噪音为1 nV/√Hz, 30 dB增益的THD+N为0.0003%.本文介绍THAT1570主要特性,方框图,以及多种应用电路.
The THAT1570 is a versatile, high performance current-feedback amplifier suitable for differential microphone preamp and bus summing applications. The IC comes in a small QFN package, which saves PCB space over discrete and other integrated solutions.
Gain is adjusted via three external resistors (RA, RB, and RG), making it possible to optimize noise over a wide range of gains. The 1570 supports the traditional approach to gain control (viz., THATs 1510 or 1512) by fixing RA and RB, and varying RG to control gain. However, the 1570 also supports varying all three resistors simultaneously with a dual-gang potentiometer or a switched resistor network. This flexible approach enables the designer to optimize noise over a wider range of gains than is possible with fixed RA and RB.
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