Black Two-wire Passive I/v Converter 2-wire Passive 4-20ma To Voltage Signal Low Cost Converter

Features:
a High efficient signal loop stealing technology, external
power supply is not required.
a 2-wire 4-20mA standard analog signal input,
output 0-2.5V/0-3.3V/0-5V/1-5V, etc standard
voltage signal.
a Extra low input impedance, meet the requirements that
when input is 20mA the voltage drop a 6V.
a Accuracy grade: 0.1, 0.2, 0.5
a High linearity in full measuring range, non-linearity error
grade <0.2%
a Industrial grade temperature range: -25 ~ +70 a
a Small size standard SIP 7Pin, UL94V-0 flame-retardant
package

Applications:
a Sensor 4-20mA signal acquisition and
conversion.
a Industrial site signal acquisition and
long-distance transmission.
a Analog signal conversion and data acquisition.
a Sensorsa or metersa Signal receiving and
transmission.
a PLC, DCS analog signal acquisition and
conversion.
a Power control, medical equipments monitoring.
a 4-20mA current signal to voltage signal
conversion: 1-IN1-OUT, 2-IN 2-OUT, 3-IN
3-OUT

Introduction
Sunyuan SY 4-20mA-O is a kind of low cost small size 2-wire passive 4-20mA to voltage conversion IC, it
can convert active 4-20mA signal input into voltage signal output. In designing the converter, 2-wire input loop
powered technique is adopted, and the external power supply is not required which simplifies customersa design
plan and reduce customersa cost. Inside the conversion IC, current signal conversion circuit, power inverting
circuit, subtraction circuit and buffered output circuit are integrated. Very low input equivalent impedance enables
the IC to collect current signals from sensor signal output loop circuit and when the input is 30mA signal the
voltage drop is a 6V. That 2-wire passive 4-20ma to voltage conversion IC achieves long-distance non-distorted
transmission without external power supply.
SY 4-20mA-O Series are mainly applied in low cost 4-20mA current to voltage signal design, no external
power supply which makes it easy in wire connection, and achieves low power consumption, low heat and high
performance. The main features of that conversion IC are: 2-wire loop powered without external power supply,
subtraction circuit and amplification buffered output circuit are integrated into the IC, high reliability and easy to
use. The converter convert 4-20mA output signal from sensor, PLC, it means that the transmission of electric
power, so there is power consumption internally. In that conditions, it requires that 4-20mA source signal should
be able to drive 300IC load, thus the converter IC can operate normally. In industrial site applications, most of
meters and instruments, sensors, PLC, DCS, etc have the capacity to drive 300IC load.
In industrial site, in some conditions only one piece of IV conversion sampling resistance is enough to
convert current signal into voltage signal. That kind of circuit is easy but not much reliable. First, when the signal
is in zero point, there is zero current in sampling resistance, for example, convert 4-0mA into max. 5VDC, in the
zero point, it is 1V after conversion, that 1V voltage can be processed by microprocessor software if available. In
that case, the available voltage left 5-1=4VDC, it is not 5VDC. The max. input voltage of microprocessor (A/D) is
ita s power supply, usually 5VDC, so it is much more complicated in deal with such simple input conversion circuits,
in order to get the A/D conversion bits, it will increase the IC costs accordingly. The simplest method in dealing
with the problems above is that adding a subtraction and buffered processing circuit made by operational
amplifier in the input terminal of microprocessor, that circuit is convenient to process zero signal and save the
microprocessor resource to ensure that all the resource is used in signal conversion especially in A-D conversion
Features Applications
a High efficient signal loop stealing technology, external
power supply is not required.
a 2-wire 4-20mA standard analog signal input,
output 0-2.5V/0-3.3V/0-5V/1-5V, etc standard
voltage signal.