PCIe-7821 Specifications

This document contains the specifications for the PCIe-7821.

Caution Using the PCIe-7821 in a manner not described in this document may impair the protection the PCIe-7821 provides.

Specifications are typical at 25 °C unless otherwise noted.

Revision History

Version Date changed Description
376830B-02 October 2025 Updated DMA quantity. Added pinout diagrams.
376830A-02 April 2017 Initial release.

Looking For Something Else?

For information not found in the specifications for your product, such as operating instructions, browse Related Information.

PCIe-7821 Pinout

Figure 1. PCIe-7821 Pinout


Table 1. Signal Descriptions
Signal Description
DIO <0...31> Digital I/O data through channels 0 through 31.
GND Ground reference for signals.
External Clock External clock input source that can be used for source synchronous acquisitions. The provided clock source must be stable and glitch-free.

Digital I/O

Table 2. Digital I/O
Number of connectors 4
Number of channels per connector 32
Maximum frequency 80 MHz
Compatibility LVTTL, LVCMOS
Logic family Software-selectable
Default software setting 3.3 V
Table 3. Digital Input Logic Levels
Logic Family Input Low Voltage (VIL) Input High Voltage (VIH)
Minimum Maximum Minimum Maximum
1.2 V -0.3 V 0.40 V 0.84 V 1.5 V
1.5 V -0.3 V 0.50 V 1.05 V 1.8 V
1.8 V -0.3 V 0.60 V 1.25 V 2.1 V
2.5 V -0.3 V 0.70 V 1.70 V 2.8 V
3.3 V -0.3 V 0.80 V 2.00 V 3.6 V
Table 4. Input
Input leakage current ±15 µA maximum
Input impedance 50 kΩ typical, pull-down
Table 5. Digital Output Logic Levels
Logic Family Current Output Low Voltage (VOL) Maximum Output High Voltage (VOH) Minimum
1.2 V 100 µA 0.20 V 1.00 V
1.5 V 100 µA 0.20 V 1.25 V
1.8 V 100 µA 0.20 V 1.54 V
2.5 V 100 µA 0.20 V 2.22 V
3.3 V 100 µA 0.20 V 3.00 V
4 mA 0.40 V 2.40 V
Table 6. Maximum DC Output Current per Channel
Source 4.0 mA
Sink 4.0 mA
Table 7. Output
Output impedance 50 Ω
Table 8. Digital I/O Power and Protection
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. ±20 V, single line
Digital I/O voltage selection Programmable, per connector, and defined at compilation (not run-time configurable)
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 9. External Clock
Direction Input into device
Maximum input leakage ±15 µA
Characteristic impedance 50 Ω
Power-on state Tristated
Minimum input Inherited from programmed digital voltage selection per connector
Maximum input Inherited from programmed digital voltage selection per connector
Logic level Inherited from programmed digital voltage selection per connector
Maximum input frequency 80 MHz

Reconfigurable FPGA

Table 10. Reconfigurable FPGA
FPGA type Kintex-7 160T
Number of flip-flops 202,800
Number of LUTs 101,400
Embedded Block RAM 11,700 kbits
Number of DSP48 slices 600
Timebase 40 MHz, 80 MHz, 120 MHz, 160 MHz, or 200 MHz
Default timebase 40 MHz
Timebase accuracy ±100 ppm, 250 ps peak-to-peak jitter
Data transfers DMA, interrupts, programmed I/O

Onboard DRAM

Table 11. Onboard DRAM
Memory size 1 Bank; 512 MB
Maximum theoretical data rate 800 MB/s streaming

Synchronization Resources

Table 12. Synchronization Resources
Input/output source RTSI<0..7>

Bus Interface

Table 13. Bus Interface
Form factor x4 PCI Express, specification v1.0 compliant
Slot compatibility x4, x8, and x16 PCI Express 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 14. 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.
Table 15. Physical Characteristics
Dimensions 18.1 cm × 12.6 cm × 2.2 cm (7.1 in. × 5.0 in. × 0.9 in.)
Weight 158 g (5.57 oz)
I/O connectors 4 × 68-pin VHDCI

Environmental

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

Table 16. Environmental
Operating temperature (IEC 60068-2-1, IEC 60068-2-2) 0 °C to 55 °C
Storage temperature (IEC 60068-2-1, IEC 60068-2-2) -40 °C to 71 °C
Operating humidity (IEC 60068-2-56) 10% RH to 90% RH, noncondensing
Storage humidity (IEC 60068-2-56) 5% RH to 95% RH, noncondensing
Pollution Degree 2
Maximum altitude 2,000 m

Indoor use only.

Safety Voltages

Connect only voltages that are below these limits.

Table 17. Safety Voltages
Channel-to-earth ±12 V, Measurement Category I
Channel-to-channel ±24 V, Measurement Category I
Caution Do not connect the PCIe-7821 to signals or use for measurements within Measurement Categories II, III, or IV.
Attention Ne connectez pas le PCIe-7821 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.

Electromagnetic Compatibility

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 B emissions; Basic immunity
  • EN 55011 (CISPR 11): Group 1, Class B emissions
  • EN 55022 (CISPR 22): Class B emissions
  • EN 55024 (CISPR 24): Immunity
  • AS/NZS CISPR 11: Group 1, Class B emissions
  • AS/NZS CISPR 22: Class B emissions
  • FCC 47 CFR Part 15B: Class B emissions
  • ICES-001: Class B emissions
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.
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 For EMC declarations and certifications, and additional information, refer to the Product Certifications and Declarations section.

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.