Analog Input
- Updated2024-04-08
- 2 minute(s) read
Analog Input
The PXIe-4309 samples up to 32 differential channels and multiplexes the analog input channels across eight simultaneously sampling ADCs.
Input signals on each channel are conditioned, buffered, and then sampled by a SAR ADC.
The PXIe-4309 provides eight independent signal conditioning paths and ADCs, enabling simultaneous sampling of up to eight input channels. Each ADC can scan through four independent input channels for a total of 32 input channels.
Source Impedance
Use a source impedance of 50 Ω or lower for optimal measurement performance. Error is introduced by source impedances greater than 50 Ω. The PXIe-4309 Specifications "Source Impedance Error" section provides additional information about this error.
Common Mode Rejection Ratio (CMMR)
The analog input circuitry is floating to provide best in class CMRR of DC common-mode voltages.
Floating analog input circuits have an inherent input impedance mismatch. To minimize the effect of this mismatch on CMRR of AC common-mode voltages, keep the DC resistance and AC impedance of the AIn- lead wire to a minimum.
Common Mode Noise
Floating power supplies inject common-mode current onto its floating ground. To minimize the effect of this current on measurement noise, keep the DC resistance and AC impedance of the AIn- lead wire to a minimum.
Shielding
Use double-shielded twisted pair cabling for optimal noise immunity.
