- Interfaces to DC Displacement Transducers and Other Devices Requiring a Stable DC Supply
- High-Level Voltage Outputs
- 1500Vrms Transformer Isolation
- ANSI/IEEE C37.90.1 Transient Protection
- Fully Isolated Excitation Supply
- 100dB CMR
- 1kHz Signal Bandwidth
- ±0.03% Accuracy / ±0.005% Linearity / ±20µV/°C Drift
- ATEX Compliant
The SCM5B43 voltage input module provides a differential, isolated, analog input channel that is filtered, isolated, amplified, and converted to an analog output voltage. This voltage output is switchable via a logic input, allowing multiple of these modules to share a common analog bus without the need for external multiplexers.
In addition to the input, the output of the module is also galvanically isolated from the module supply. The galvanic isolation provides additional safety in industrial applications and reliably protects the downstream evaluation electronics. The SCM5B43 can interface to devices which require a precision 10VDC excitation supply. The 1kHz bandwidth significantly reduces ripple and noise inherent in these devices.
Transducer excitation is provided from the module by a very stable 10V source. The excitation supply is fully isolated, allowing the amplifier inputs to operate over the full range of the excitation voltage. This feature offers significant flexibility in real world applications. Eight full scale input ranges are provided, from ±1V to ±10V, producing ±5V full scale Output. Signal filtering is provided by a six-pole filter that offers 95dB suppression at 60Hz and 90dB at 50Hz. Two poles of this filter are located on the field side of the isolation barrier, the other four on the output side.
After upstream field-side filtering, the input signal is chopped by a proprietary chopper circuit. Isolation is provided by a signal transformer, with a proprietary technique for suppressing transmission of common-mode spikes or surges. The module is powered from +5VDC, ±5%. A special input circuit on the SCM5B43 modules provides protection against accidental connection of power-line voltages up to 240VAC.