The MTT MS3773 Slim Plug-In Programmable Millivolt Isolator takes a low-level DC millivolt signal from a sensor and converts it into a standard isolated current or voltage output, with the input range and output configuration set through PC software rather than fixed at the factory. This makes it a flexible replacement for a family of dedicated millivolt isolator models, since one MS3773 can be reconfigured for a different millivolt range or output type as project requirements change.
Configuration is carried out from a PC over an RS-232C connection, where the module can also be set up with a configurable 6th-order polynomial linearization to correct for non-linear sensor characteristics, going beyond simple straight-line scaling. Selectable burnout protection drives the output upscale or downscale if the input signal is lost, and an LED status indicator reports run, fail, and error states at a glance. Four-way isolation between input, output, and power keeps the converted signal protected from noise and ground loops.
| Input Resistance | 1MΩ min. |
| Input Ranges | 20mV, 40mV, 80mV, 160mV, 320mV, 640mV, 1V, 2V |
| Allowable Input Voltage | 25V DC continuous |
| Burnout Protection | Selectable upscale/downscale (approx. 55nA detection current); drive time 80s max (160s for 1V range, 480s for 2V range) |
| Output Options | Single: 4-20mA DC, 0-10V DC, 0-5V DC, 1-5V DC; Dual: 4-20mA/1-5V DC, 4-20mA/4-20mA DC, voltage combinations |
| Output Load | 2mA max (voltage); 750Ω max (single 4-20mA); 550Ω/350Ω (dual) |
| Adjustment | Approx. ±4% of span, zero and span, configured via RS-232C |
| Input Accuracy | 0.02% of range/span (excluding linearity error) |
| Output Accuracy | ±0.04% max |
| Temperature Effect | 100ppm/°C max |
| Response Time | 260ms max (0-90%, step input at 100%) |
| CMRR | 100dB min. |
| Isolation | 4-way isolation between input, output, power, and ground; 100MΩ min. insulation resistance @500V DC; 2000V AC dielectric strength for 1 minute |
| Power Supply | 100-240V AC, 24V DC, or 100-240V DC; 5.0VA max (single, AC) / 1.1-1.5W (24V DC) / 4.8-6.0W (100-240V DC); 160mA fuse standard |
| Dimensions | W29 x H86 x D125mm (including mounting hardware) |
| Weight | 120g (main unit) / 80g (socket) max |
| Terminals | M3.5 screw terminals, 0.8-1.0 Nm torque |
| Mounting | Wall or DIN rail mount |
| Operating Conditions | -5 to 55°C, 5-90% RH non-condensing |
| Storage Temperature | -10 to 60°C |
| Additional Features | Configurable 6th-order polynomial linearization; RS-232C PC configuration; LED status indicator (RUN/FAIL/ERROR); optional high-load output protection (/L option) |
Frequently Asked Questions
What is the MTT MS3773 used for?
It converts a low-level DC millivolt signal from a sensor into a standard isolated current or voltage output, with the input range and output configuration set through PC software rather than fixed at the factory. One MS3773 can be reconfigured for a different millivolt range or output type, in place of stocking a separate fixed-range isolator for each application.
What input ranges does it support?
20mV, 40mV, 80mV, 160mV, 320mV, 640mV, 1V, and 2V, selected in configuration rather than by model number. Tell us your sensor’s millivolt output range and we can confirm the setup.
Can it correct for a non-linear sensor signal?
Yes. The MS3773 supports a configurable 6th-order polynomial linearization in addition to simple straight-line scaling, so a sensor with a non-linear millivolt-to-measurement relationship can still be converted into an accurate, linear output signal.
What happens if the input signal is lost?
Burnout protection is selectable: the output drives either full upscale or full downscale if the input is lost, with a detection current of about 55nA, so your control system sees a defined fault condition rather than a stale or misleading reading.
How do I know if the MS3773 is right for my application?
If you have a low-level millivolt signal that needs isolating and converting to a standard current or voltage output, with the option of custom linearization for a non-linear sensor, the MS3773 is built for that. Send us your input range, linearity requirements, and desired output signal and we’ll confirm before you order.
Download MTT MS3773 Slim Plug-In Programmable Millivolt Isolator information here
Datasheet: MTT_SpecSheet_MS3773_Rev23_E
