Study and design of small signal isolating transmitter

When acquiring analog signal in industrial process control, the ground loop current and noise should be effectively eliminated to show the authenticity of the signal acquired. This is particularly important when sampling very small voltages (mV) or currents (mA) DC signal. This paper explains the design of a DC isolating transmitter for small signal. The transmitter is practical and consists of DC power isolating module and signal isolating transmitter module. It has a capability range of 0~75mV inputs to 0~10 V outputs. Test results clearly show that the transmitter has a high degree of linearity and fast response, with a good isolation and high anti-interference capability.