The OP5340-1 module provides 16 differential analog input channels, sampled at up to 400 kS/s, for measuring ±20V input signals.
An 8-channel version of the module previously available, the OP5340-2, is now discontinued.
- 16 analog input channels
- 16-bit resolution
- Simultaneous sampling at 400 kS/s
- Voltage range ±20V
The OP5340-1 module uses eight 16-bit dual-channel analog to digital converters. The figure below represents a simplified schematic of one channel. It is composed of three stages:
- the first stage consists of one operational amplifier that works in differential input mode and allows gain adjustment;
- the second stage, the level shifter, adapts the signal for the A/D converter input;
- the third stage consists of the conversion by the A/D converter of the input signal into a digital signal which is transferred via the carrier board to the FPGA chip of the real-time simulator.
The default voltage range is ±20V. This value is obtained by using two resistor values, R1 and R2, to form the input stage :
The Vout value at the output of the amplifier is then obtained by the formula :
In order to keep the Vout range at ±1 V, which maximizes the precision of the measurement, the resistor values are set to R1 = 499 kΩ and R2 = 25 kΩ :
The channel gain obtained with the default R1, R2 values is thus 1/20 :
- The card is factory-calibrated to ensure accurate output values with a maximum of ±20 mV absolute error on noise and offset.