MTL4644D Repeater Power Supply | MTL

MTL4644D Repeater Power Supply for 4/20mA and HART

The MTL4644D delivers a fully floating DC supply for conventional 2-wire or 3-wire transmitters. It repeats the 4/20mA current into two separate load circuits. For HART 2-wire transmitters, this model allows bidirectional digital communication. The digital signals are superimposed on the 4/20mA loop current. Therefore, you can maintain both analog and digital communication simultaneously.

Key Technical Specifications

Output signal range: 4 to 20mA (under/over-range: 0 to 24mA).
Load resistance at 24mA is 0 to 360Ω. At 20mA, it is 0 to 450Ω.
Circuit output resistance exceeds 1MΩ. Ripple is less than 50µA peak-to-peak.
Input signal range: 0 to 24mA including over-range.
Transmitter voltage: 16.5V at 20mA.
Transfer accuracy at 20°C is better than 15µA.
Temperature drift remains below 0.8µA/°C.
Response time settles to within 10% of final value within 50µs.

Communication and Indicators

This MTL4644D supports HART communication via terminals 1 and 2 on output channel 1 only. A green LED indicates power status. Maximum current consumption is 96mA at 24V DC. Power dissipation inside the unit is 1.4W at 24V DC.

Mechanical and Environmental Data

The MTL4644D uses a compact housing for DIN-rail mounting. It operates in a temperature range of -20°C to +60°C. Humidity tolerance is 5% to 95% non-condensing. Furthermore, the unit meets standard industrial safety requirements. It provides isolation between input, output, and power circuits.

Frequently Asked Questions (FAQ)

1. Can the MTL4644D work with both 2-wire and 3-wire transmitters?
Yes, the MTL4644D supports both 2-wire and 3-wire 4/20mA transmitters without any configuration change.

2. Does this unit support HART on both output channels?
No, HART communication is supported only on output channel 1 (terminals 1 and 2). Channel 2 does not pass HART signals.

3. What happens if the input current exceeds 20mA?
The MTL4644D accepts up to 24mA including over-range. The output follows the input linearly within this range.

4. How fast does the output respond to input changes?
The output settles to within 10% of the final value in under 50µs. Therefore, it works well for fast control loops.

5. Can I use this repeater in a hazardous area?
The MTL4644D is designed for safe area installations. For hazardous locations, you need additional galvanic isolators or barriers. Always check local regulations before installation.