Transmitter converting current to voltage

Abstract

The invention discloses a transmitter converting current to voltage. The transmitter comprises a current source circuit, a current converting circuit, and a voltage converting circuit. The current source circuit is used to provide stable direct current for the current converting circuit. The current converting circuit is used to convert an input first current range to a second current range. The voltage converting circuit is used to convert the second current range to a preset voltage range. The transmitter is a universal transmitter which can convert a standard 4-20 mA current signal output by a sensor to a 0-5 V voltage signal which meets input requirements of an analog-digital converter. The transmitter is suitable to be used in operation temperature of 25 DEG C to 85 DEG C, and is small in volume and high in converting precision.

Description

technical field

[0001] The invention belongs to the field of circuit design, in particular to a transmitter for converting current to voltage. Background technique

[0002] In many industrial applications, sensors are needed, such as pressure sensors, temperature sensors, etc. In order to meet long-distance transmission and anti-interference, the output of most sensors is a standard 4-20mA current signal, but the input of the analog-to-digital converter ADC generally requires a 0-5V voltage signal. Although there are 4-20mA to 0-5V modules on the market, they are very bulky and not suitable for high-density circuits; moreover, the conversion error is relatively large, so they are not suitable for occasions with high performance requirements. Although Burr Brown Company once launched a dedicated conversion chip RCV420, the chip can only work at a temperature of 0°C to 70°C, which greatly limits the practicability of the chip. So the present invention designs a kind of. Co...

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