一种新型的XTR104应用电路

New application circuit of XTR104

XTR104作为电桥信号输入式4～20mA二线电流变送器,在其基本应用电路中,参考电源VR可直接驱动2750Ω以上的应变电桥传感器;对于350Ω的电桥,通过串联电阻来限制激励电流不大于2mA。文中通过分析,提出了在350Ω电桥应用中,采用射极跟随器来减小XTR104参考电源的输出电流,但能保持较大激励电压的电路结构形式。对于由此附加的静态电流,利用恒流源分流的方式消除其影响。

The XTR104 is a monolithic 4～20mA , two-wire current transmitter integrated circuit designed for bridge input signals. In the basic application for the XTR104, a high impedance (≥2750Ω) strain gage sensor can be excited directly by the reference output terminal VR for 350Ωbridges can be used by adding series resistance to limit excitation current to V≤2mA. This paper gives out a new connection diagram for 350Ωbridge, emitter follower is used to reduce excitation current of VR. The appended quiet current can be eliminated by constant current source division.