PXIe-7868 Specifications

PXIe-7868 Specifications

This document contains the specifications for the PXIe-7868.

Revision History

Version Date changed Description
379102B-01 October 2025 Updated DMA quantity.
379102A-01 December 2024 Added pinout diagrams.
378036A-02 May 2017 Original specifications document: NI PXIe-7868R Specifications.

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Conditions

The following specifications are typical at 25 °C unless otherwise noted.

PXIe-7868 Pinout

Figure 1. PXIe-7868 Pinout


Table 1. PXIe-7868 Signal Descriptions
Signal Description
AI+ Positive analog input signal connection
AI- Negative analog input signal connection
AISENSE Reference connection for NRSE measurements
AIGND Ground reference for the analog input signal
AO Analog output signal connection
AOGND Ground reference for the analog output signal
DIO Digital input/output signal connection
DGND Ground reference for the digital signal
EXTCLKIN External clock input source that can be used for source synchronous acquisitions. The provided clock source must be stable and glitch-free.
GND Ground connection
Supply (+5 Vout) 5 V power output connection for external devices
NC No connection

The PXIe-7868 is protected from overvoltage and overcurrent conditions.

Note The pinout label on the lid of the SCB-68A accessory is incompatible with the PXIe-7868. Refer to the NI 78xxR and NI 78xx Pinout Labels for the SCB-68A Note to Users for the compatible pinout labels.

Analog Input

Table 2. Analog Input
Number of channels 6
Input modes (software-selectable; selection applies to all channels) DIFF, NRSE, RSE
Type of ADC Successive approximation register (SAR)
Resolution 16 bits
Conversion time 1 µs
Maximum sampling rate (per channel) 1 MS/s
Input signal range (software-selectable) ±1 V, ±2 V, ±5 V, ±10 V
Input bias current ±5 nA
Input offset current ±5 nA
Input coupling DC
Table 3. Input Impedance
Powered on 1.25 GΩ ║ 2 pF
Powered off/overload 4 kΩ minimum
Table 4. Overvoltage Protection
Powered on ±42 V maximum
Powered off ±35 V maximum
Table 5. AI Operating Voltage Ranges Over Temperature
Range (V) Measurement Voltage, AI+ to AI- Maximum Working Voltage (Signal + Common Mode)
Minimum (V)* Typical (V) Maximum (V)
±10 ±10.37 ±10.5 ±10.63 ±12 V of ground
±5 ±5.18 ± 5.25 ±5.32 ±10 V of ground
±2 ±2.07 ±2.1 ±2.13 ±8.5 V of ground
±1 ±1.03 ±1.05 ±1.06 ±8 V of ground
* The minimum measurement voltage range is the largest voltage the PXIe-7868 is guaranteed to accurately measure.

AI Absolute Accuracy

Absolute accuracy at full scale numbers is valid immediately following internal calibration and assumes the device is operating within 10 °C of the last external calibration. Accuracies listed are valid for up to one year from the device external calibration.

Absolute accuracy at full scale on the analog input channels is determined using the following assumptions:
  • TempChangeFromLastExternalCal = 10 °C
  • TempChangeFromLastInternalCal = 1 °C
  • number_of_readings = 10,000
  • CoverageFactor = 3 σ
Table 6. AI Absolute Accuracy (Calibrated)
Specifications Range
±10 V ±5 V ±2 V ±1 V
Residual Gain Error (ppm of Reading) 104.4 105.9 110.6 118.4
Gain Tempco (ppm/°C) 20 20 20 20
Reference Tempco (ppm/°C) 4 4 4 4
Residual Offset Error (ppm of Range) 16.4 16.4 16.4 16.4
Offset Tempco (ppm of Range/°C) 4.18 4.17 4.41 4.63
INL Error (ppm of range) 42.52 46.52 46.52 50.52
Random Noise, σ (µVrms) 263 156 90 74
Absolute Accuracy at Full Scale (µV) 2,283 1,170 479 252
Table 7. AI Absolute Accuracy (Uncalibrated)
Specifications Range
±10 V ±5 V ±2 V ±1 V
Residual Gain Error (ppm of Reading) 2,921 3,021 3,021 3,021
Gain Tempco (ppm/°C) 20 20 20 20
Reference Tempco (ppm/°C) 4 4 4 4
Residual Offset Error (ppm of Range) 661 671 700 631
Offset Tempco (ppm of Range/°C) 4.18 4.17 4.41 4.63
INL Error (ppm of range) 42.52 46.52 46.52 50.52
Random Noise, σ (µVrms) 263 156 90 74
Absolute Accuracy at Full Scale (µV) 36,895 19,018 7,667 3,769

Calculating Absolute Accuracy

AbsoluteAccuracy = Reading × ( GainError ) + Range ⁢ × ( OffsetError ) + NoiseUncertainty
GainError = ResidualGainError + GainTempco × ( TempChangeFromLastInternalCal ) + ReferenceTempco × ( TempChangeFromLastExternalCal )
OffsetError = ResidualOffsetError + OffsetTempco   × ( TempChangeFromLastInternalCal ) + INL_Error
NoiseUncertainty = RandomNoise   ×   CoverageFactor number_of_readings ⁢

Refer to the following equation for an example of calculating absolute accuracy for a 10 V reading.

Absolute accuracy at full scale on the analog input channels is determined using the following assumptions:
  • TempChangeFromLastExternalCal = 10 °C
  • TempChangeFromLastInternalCal = 1 °C
  • number_of_readings = 10,000
  • CoverageFactor = 3 σ
GainError = 104.4   ppm + 20   ppm × 1 + 4     ppm × 10
GainError = 164.4     ppm
OffsetError = 16.4   ppm + 4.18     ppm   1 + 42.52     ppm
OffsetError = 63.1   ppm
NoiseUncertainty = 263   µV ⁢ ×   3 10,000 ⁢
NoiseUncertainty = 7.89   µV
AbsoluteAccuracy = 10   V × ( GainError ) + 10   V ⁢ × ( OffsetError ) + NoiseUncertainty
AbsoluteAccuracy = 2,283   µV

DC Transfer Characteristics

Table 8. DC Transfer Characteristics
INL Refer to the AI Absolute Accuracy tables
DNL ±0.4 LSB typical, ±0.9 LSB maximum
No missing codes 16 bits guaranteed
CMRR, DC to 60 Hz -100 dB

Dynamic Characteristics

Table 9. Dynamic Characteristics
Small signal bandwidth 1 MHz
Large signal bandwidth 500 kHz
Table 10. Settling Time
Range (V) Step Size (V) Accuracy
±16 LSB ±4 LSB ±2 LSB
±10 ±20.0 1.50 µs 4.00 µs 7.00 µs
±2.0 0.50 µs 0.50 µs 1.00 µs
±0.2 0.50 µs 0.50 µs 0.50 µs
±5 ±10 1.50 µs 3.50 µs 7.50 µs
±1 0.50 µs 0.50 µs 1.00 µs
±0.1 0.50 µs 0.50 µs 0.50 µs
±2 ±4 1.00 µs 3.50 µs 8.00 µs
±0.4 0.50 µs 0.50 µs 1.00 µs
±0.04 0.50 µs 0.50 µs 0.50 µs
±1 ±2 1.00 µs 3.50 µs 12.00 µs
±0.2 0.50 µs 0.50 µs 2.00 µs
±0.02 0.50 µs 0.50 µs 0.50 µs
Table 11. Crosstalk
Crosstalk -80 dB, DC to 100 kHz, at 50 Ω

Analog Output

Table 12. Analog Output
Output type Single-ended, voltage output
Number of channels 18
Resolution 16 bits
Update time 1 μs
Maximum update rate 1 MS/s
Type of DAC Enhanced R-2R
Range ±10 V
Output coupling DC
Output impedance 0.5 Ω
Current drive ±2.5 mA
Protection Short circuit to ground
Table 13. Overvoltage Protection
Powered on ±15 V maximum
Powered off ±10 V maximum
Table 14. Power-On State and Power-On Glitch
Power-on state User-configurable
Power-on glitch 1 V for 1 µs
Power-down glitch 3.7 V peak, decays to 0 V in 7 ms
Table 15. AO Operating Voltage Ranges for Over Temperature
Range (V) Measurement Voltage, AO+ to AO GND
Minimum (V)* Typical (V) Maximum (V)
±10 ±10.1 ±10.16 ±10.22
* The minimum measurement voltage range is the largest voltage the PXIe-7868 is guaranteed to accurately measure.

AO Absolute Accuracy

Absolute accuracy at full scale numbers is valid immediately following internal calibration and assumes the device is operating within 10 °C of the last external calibration. Accuracies listed are valid for up to one year from the device external calibration.

Absolute accuracy at full scale on the analog output channels is determined using the following assumptions:

  • TempChangeFromLastExternalCal = 10 °C
  • TempChangeFromLastInternalCal = 1 °C
Table 16. AO Absolute Accuracy (Calibrated)
Specifications ±10 V Range
Residual Gain Error (ppm of Reading) 87.3
Gain Tempco (ppm/°C) 12.6
Reference Tempco (ppm/°C) 4
Residual Offset Error (ppm of Range) 41.1
Offset Tempco (ppm of Range/°C) 7.8
INL Error (ppm of range) 61
Absolute Accuracy at Full Scale (µV) 2,498
Table 17. AO Absolute Accuracy (Uncalibrated)
Specifications ±10 V Range
Residual Gain Error (ppm of Reading) 2,968.6
Gain Tempco (ppm/°C) 12.6
Reference Tempco (ppm/°C) 4
Residual Offset Error (ppm of Range) 1,004.1
Offset Tempco (ppm of Range/°C) 7.8
INL Error (ppm of range) 61
Absolute Accuracy at Full Scale (µV) 40,941

Calculating Absolute Accuracy

AbsoluteAccuracy = OutputValue × ( GainError ) + Range × ( OffsetError )
GainError = ResidualGainError + GainTempco × ( TempChangeFromLastInternalCal ) + ReferenceTempco × ( TempChangeFromLastExternalCal )
OffsetError = ResidualGainError + AOOffsetTempco × ( TempChangeFromLastInternalCal ) + INL_Error

Refer to the following equation for an example of calculating absolute accuracy for a 10 V reading.

Absolute accuracy at full scale on the analog output channels is determined using the following assumptions:
  • TempChangeFromLastExternalCal = 10 °C
  • TempChangeFromLastInternalCal = 1 °C
GainError = 87.3   ppm + 12.6   ppm ×   1 + 4   ppm ×   10
GainError = 139.9   ppm
OffsetError = 41.1   ppm + 7.8   ppm ×   1 + 61   ppm
OffsetError = 109.9   ppm
AbsoluteAccuracy = 10   V × ( GainError ) + 10   V × ( OffsetError )
AbsoluteAccuracy = 2,498   µV

DC Transfer Characteristics

Table 18. DC Transfer Characteristics
INL Refer to the AO Absolute Accuracy tables
DNL ±0.5 LSB typical, ±1 LSB maximum
Monotonicity 16 bits, guaranteed

Dynamic Characteristics

Table 19. Settling Time
Step Size (V) Accuracy
±16 LSB ±4 LSB ±2 LSB
±20.0 5.3 µs 6.5 µs 7.8 µs
±2.0 3.2 µs 3.9 µs 4.4 µs
±0.2 1.8 µs 2.8 µs 3.8 µs
Table 20. Dynamic Characteristics
Slew rate 10 V/µs
Noise 250 µV RMS, DC to 1 MHz
Glitch energy at midscale transition ±10 mV for 3 µs

5V Output

Table 21. 5V Output
Output voltage 4.75 V to 5.1 V
Output current 0.5 A maximum
Overvoltage protection ±30 V
Overcurrent protection 650 mA

Digital I/O

Table 22. Channel Frequency
Connector Number of Channels Maximum Frequency
Connector 0 16 10 MHz
Connector 1 32 80 MHz
Table 23. Digital I/O
Compatibility LVTTL, LVCMOS
Logic family Fixed
Voltage level 3.3 V
Table 24. Input
Minimum input -0.3 V
Maximum input 3.6 V
Input leakage current ±15 µA maximum
Input impedance 50 kΩ typical, pull-down
Table 25. Digital Input Logic Levels
Logic Family Input Low Voltage (VIL) Maximum Input High Voltage (VIH) Minimum
3.3 V 0.80 V 2.00 V
Table 26. Digital Output Logic Levels
Logic Family Current Output Low Voltage (VOL) Maximum Output High Voltage (VOH) Minimum
3.3 V 100 µA 0.20 V 3.00 V
4 mA 0.40 V 2.40 V
Table 27. Maximum DC Output Current per Channel
Source 4.0 mA
Sink 4.0 mA
Table 28. Digital I/O
Output impedance 50 Ω
Power-on state (tristate by default) Programmable, by line
Protection[1]1 NI recommends minimizing long-term over/under-voltage exposure to the digital I/O. Prolonged DC voltage stresses that violate the maximum and minimum digital input voltage ratings may reduce device longevity. Over/under-voltage stresses are considered prolonged if the cumulative time in the abnormal condition exceeds 1 year. ±15 V, single line
Direction control of digital I/O channels Per channel
Minimum I/O pulse width 6.25 ns
Minimum sampling period 5 ns

External Clock

Table 29. External Clock
Direction Input into device
Maximum input leakage ±15 µA
Characteristic impedance 50 Ω
Power-on state Tristated
Minimum input -0.3 V
Maximum input 3.6 V
Logic level 3.3 V
Maximum input frequency 80 MHz

Reconfigurable FPGA

Table 30. Reconfigurable FPGA
FPGA type Kintex-7 325T
Number of flip-flops 407,600
Number of LUTs 203,800
Embedded Block RAM 16,020 kbits
Number of DSP48 slices 840
Timebase 40 MHz, 80 MHz, 120 MHz, 160 MHz, or 200 MHz
Default timebase 40 MHz
Timebase reference source Onboard clock, phase-locked to PXI Express100 MHz (PXIe_CLK100)
Onboard clock timebase accuracy ±100 ppm, 250 ps peak-to-peak jitter
Data transfers DMA, interrupts, programmed I/O

Onboard DRAM

Table 31. Onboard DRAM
Memory size 1 Bank; 512 MB
Maximum theoretical data rate 800 MB/s streaming

Synchronization Resources

Table 32. Synchronization Resources
Input/output source PXI_Trig<0..7>
Input source PXI_Star, PXIe_DStarA, PXIe_DStarB, PXI_Clk10, PXIe_Clk100, External Clock 1
Output source PXIe_DStarC

Bus Interface

Table 33. Bus Interface
Form factor x4 PXI Express, specification v1.0 compliant
Slot compatibility x4, x8, and x16 PXI Express or PXI Express hybrid slots
Data transfers DMA, interrupts, programmed I/O
Number of DMA channels 15

Power Requirements

Power requirements are dependent on the digital output loads and configuration of the LabVIEW FPGA VI used in your application.

Table 34. Maximum Power Requirements
+3.3 V 3 A
+12 V 2 A

Physical Characteristics

Note If you need to clean the device, wipe it with a dry, clean towel.
Tip For two-dimensional drawings and three-dimensional models of the device and connectors, visit ni.com/dimensions and search by model number.
Table 35. Physical Characteristics
Dimensions 18.5 cm × 17.3 cm × 3.6 cm(7.3 in. × 6.8 in. × 1.4 in.)
Weight 176.3 g (6.22 oz)
I/O connectors 3 × 68-pin VHDCI

Environmental

Refer to the manual for the chassis you are using for more information about meeting these specifications.

Table 36. Environmental
Operating temperature 0 °C to 55 °C
Storage temperature -40 °C to 71 °C
Operating humidity 10% RH to 90% RH, noncondensing
Storage humidity 5% RH to 95% RH, noncondensing
Pollution Degree 2
Maximum altitude 2,000 m

Indoor use only.

Shock and Vibration

Table 37. Shock and Vibration
Operational shock 30 g PK, half-sine, 11 ms pulse
Random vibration, operating 5 Hz to 500 Hz, 0.3 g RMS
Random vibration, non-operating 2.4 g RMS

Calibration

Table 38. Calibration
Recommended warm-up time 15 minutes
Calibration interval 1 year
Table 39. Onboard Calibration Reference
DC level (actual value stored in flash memory) 5.000 V (±2 mV)
Temperature coefficient ±4 ppm/°C maximum
Long-term stability ±25 ppm/1,000 h
Note Refer to Calibration Certifications at ni.com/calibration to generate a calibration certificate for the PXIe-7868.

Safety Voltages

Connect only voltages that are below these limits.

Table 40. Safety Voltages
Channel-to-earth ±12 V, Measurement Category I
Channel-to-channel ±24 V, Measurement Category I
Caution Do not connect the PXIe-7868 to signals or use for measurements within Measurement Categories II, III, or IV.
Attention Ne connectez pas le PXIe-7868 à des signaux et ne l'utilisez pas pour effectuer des mesures dans les catégories de mesure II, III ou IV.

Measurement Category I is for measurements performed on circuits not directly connected to the electrical distribution system referred to as MAINS voltage. MAINS is a hazardous live electrical supply system that powers equipment. This category is for measurements of voltages from specially protected secondary circuits. Such voltage measurements include signal levels, special equipment, limited-energy parts of equipment, circuits powered by regulated low-voltage sources, and electronics.

Note Measurement Categories CAT I and CAT O are equivalent. These test and measurement circuits are for other circuits not intended for direct connection to the MAINS building installations of Measurement Categories CAT II, CAT III, or CAT IV.

Safety Compliance Standards

This product is designed to meet the requirements of the following electrical equipment safety standards for measurement, control, and laboratory use:

  • IEC 61010-1, EN 61010-1
  • UL 61010-1, CSA C22.2 No. 61010-1
Note For safety certifications, refer to the product label or the Product Certifications and Declarations section.

EMC Standards

This product meets the requirements of the following EMC standards for electrical equipment for measurement, control, and laboratory use:

  • EN 61326-1 (IEC 61326-1): Class A emissions; Basic immunity
  • EN 55011 (CISPR 11): Group 1, Class A emissions
  • EN 55022 (CISPR 22): Class A emissions
  • EN 55024 (CISPR 24): Immunity
  • AS/NZS CISPR 11: Group 1, Class A emissions
  • AS/NZS CISPR 22: Class A emissions
  • FCC 47 CFR Part 15B: Class A emissions
  • ICES-001: Class A emissions
Note In the United States (per FCC 47 CFR), Class A equipment is intended for use in commercial, light-industrial, and heavy-industrial locations. In Europe, Canada, Australia and New Zealand (per CISPR 11) Class A equipment is intended for use only in heavy-industrial locations.
Note Group 1 equipment (per CISPR 11) is any industrial, scientific, or medical equipment that does not intentionally generate radio frequency energy for the treatment of material or inspection/analysis purposes.

CE Compliance

This product meets the essential requirements of applicable European Directives, as follows:

  • 2014/35/EU; Low-Voltage Directive (safety)
  • 2014/30/EU; Electromagnetic Compatibility Directive (EMC)

Product Certifications and Declarations

Refer to the product Declaration of Conformity (DoC) for additional regulatory compliance information. To obtain product certifications and the DoC for NI products, visit ni.com/product-certifications, search by model number, and click the appropriate link.

Environmental Management

NI is committed to designing and manufacturing products in an environmentally responsible manner. NI recognizes that eliminating certain hazardous substances from our products is beneficial to the environment and to NI customers.

For additional environmental information, refer to the Engineering a Healthy Planet web page at ni.com/environment. This page contains the environmental regulations and directives with which NI complies, as well as other environmental information not included in this document.

EU and UK Customers

  • Waste Electrical and Electronic Equipment (WEEE)—At the end of the product life cycle, all NI products must be disposed of according to local laws and regulations. For more information about how to recycle NI products in your region, visit ni.com/environment/weee.

    • 电子信息产品污染控制管理办法（中国RoHS）

  • 中国RoHS— NI符合中国电子信息产品中限制使用某些有害物质指令(RoHS)。关于NI中国RoHS合规性信息，请登录 ni.com/environment/rohs_china。(For information about China RoHS compliance, go to ni.com/environment/rohs_china.)

    • 1 NI recommends minimizing long-term over/under-voltage exposure to the digital I/O. Prolonged DC voltage stresses that violate the maximum and minimum digital input voltage ratings may reduce device longevity. Over/under-voltage stresses are considered prolonged if the cumulative time in the abnormal condition exceeds 1 year.