The MTL5541 is a 1-channel galvanic isolated barrier from the MTL5500 Series, designed to provide intrinsic safety for 2- or 3-wire 4-20mA transmitters located in hazardous areas (Zone 0, IIC, T4-6). It supplies fully floating DC power to the transmitter and repeats the current in the isolated output circuit, eliminating the need for a high-integrity earth ground required by traditional shunt diode safety barriers. The module is HART transparent, allowing 2-way HART communication for 2-wire transmitters installed in hazardous areas.
Number of Channels: 1
Location of Transmitter: Zone 0, IIC, T4-6 hazardous area
Safe-Area Output Signal Range: 4 to 20mA
Under/Over-Range: 0 to 24mA
Safe-Area Load Resistance @ 24mA: 0 to 360Ω; @ 20mA: 0 to 450Ω
Current Sink: 600Ω max
Maximum Voltage Source: 24V DC
Hazardous-Area Input Signal Range: 0 to 24mA (including over-range)
Transmitter Voltage: 16.5V at 20mA
Transfer Accuracy at 20°C: Better than 15µA
Temperature Drift:<0.8µA/°C
Response Time: Settles within 10% of final value within 50µs
Communications Supported: HART (terminals 1 & 2 only)
LED Indicator: Green: power indication
Maximum Current Consumption: 51mA at 24V (with 20mA signal)
Power Dissipation Within Unit: 0.7W @ 24V DC (with 20mA signal)
Isolation: 250V RMS between safe- and hazardous-area terminals; tested at 1500V RMS minimum; 50V isolation between safe area & power supply
Safety Description: Simple apparatus ≤1.5V, ≤0.1A and ≤25mW; can be connected without further certification into any IS loop with an open-circuit voltage

The MTL5541 provides total intrinsically safe isolation for communication with transmitters approved for use in hazardous areas. Its galvanic isolation eliminates the need for a high integrity earth ground required when using shunt-type diode safety barriers. The module is suitable for 2 and 3 wire temperature transmitters located in hazardous areas and supports HART communication for 2-wire transmitters installed in hazardous areas. The device features 3-port isolation as standard, with isolation between safe- and hazardous-area terminals at 250V RMS, tested at 1500V RMS minimum, and 50V isolation between safe area and power supply. The hazardous-area input accepts 0 to 24mA including over-range.
The MTL5541 is used in chemical and petrochemical plants for isolating 4-20mA loops in hazardous areas, oil and gas facilities for monitoring pressure and temperature transmitters, pharmaceutical manufacturing for sterile process monitoring, power generation for turbine and boiler instrumentation, and water/wastewater treatment for chemical dosing and level monitoring.



