Last Revised: 2013-03-19 09:30:02.0
|
|
|
|

Table 1. Key Typical Specifications of the NI 5751
Combined with an NI FlexRIO FPGA module, the NI 5751 provides a powerful solution for applications requiring a high-channel-count digitizer with low crosstalk, the small form factor and scalability of PXI, and a user-accessible FPGA for custom real-time processing.

Figure 1. NI 5751 Characteristic Dynamic Performance, Spectrum – 64 k Samples, 5.3 MHz, -1 dBFS Input Signal

Table 2. Applications and Example Algorithms for the NI 5751
The NI FlexRIO family consists of PXI and PXI Express field-programmable gate array (FPGA) modules coupled to I/O adapter modules. Programmed with the NI LabVIEW FPGA Module, these modules together provide high-performance I/O and user-defined hardware processing on the PXI platform.

Figure 2. NI FlexRIO Architecture
NI FlexRIO FPGA modules feature the latest in FPGA technology and high-performance bus interfaces.

Table 3. NI FlexRIO FPGA Module Options
PXI Express NI FlexRIO FPGA modules feature Xilinx Virtex-5 SXT FPGAs with up to 512 MB of onboard DRAM, which you can access at bandwidths up to 3.2 GB/s. In addition to general-purpose reconfigurable logic, SXT FPGAs are optimized for high-speed digital signal processing (DSP), with up to 640 DSP slices for single-cycle multiplication and filtering functions. PXI Express NI FlexRIO FPGA modules also feature the NI STC-3 application-specific integrated circuit (ASIC), providing an optimized, high-bandwidth PCI Express x4 communications link to the backplane of the PXI Express chassis. This ASIC reduces the FPGA resources needed to implement host communication and enables new data transfer technology in the unique peer-to-peer (P2P) streaming feature. With NI P2P data streaming technology, you can continuously transfer data to and from PXI Express NI FlexRIO FPGA modules at rates greater than 800 MB/s for additional processing and I/O integration. You can also stream to and from select PXI Express NI modular instruments for an even greater variety of I/O.
PXI NI FlexRIO FPGA modules feature Xilinx Virtex-5 LX FPGAs with up to 128 MB of onboard DRAM, which you can access at bandwidths up to 1.6 GB/s. They feature all the benefits of the PXI platform including synchronization, triggering, and high-speed data transfer to and from their host.

Table 4. PXI and PXI Express FPGA Module Comparison
National Instruments and third parties offer NI FlexRIO adapter modules, and you can build your own adapter modules using the NI FlexRIO Adapter Module Development Kit (MDK). With custom adapter modules, you can implement the exact analog and digital I/O your application requires, along with graphical FPGA programming provided by LabVIEW. View a current list of NI and third-party adapter modules at ni.com/flexrio. This ability to easily create high-bandwidth P2P data streams helps provide scalable signal processing and I/O integration.
With the high-level graphical programming capabilities of LabVIEW FPGA, programming for the NI 5751 is far simpler than low-level HDL programming. Acquiring samples from one NI FlexRIO digitizer adapter module's analog-to-digital converter at its configured rate and placing the data into an FPGA FIFO is depicted in Figure 3.

Figure 3. LabVIEW FPGA Code for Acquiring Data from an NI FlexRIO Digitizer Adapter Module
From this point, you may implement your own processing, filtering, fast Fourier transform (FFT), or control. Figure 4 shows custom demodulation using IP from the FPGA RF Communications Library on ni.com/labs.

Figure 4. LabVIEW FPGA Code for Demodulating and Decoding I and Q Signals after 4X Decimation
For implementing a real-time spectrum analyzer, Figure 5 shows code that performs windowing, conversion to the frequency domain, comparison against a frequency mask, and assertion of a trigger when that mask is exceeded.

Figure 5. LabVIEW FPGA Code for a Real-Time Spectrum Analyzer
Finally, Figure 6 shows a custom, 128-tap inline finite impulse response (FIR) filter with reloadable coefficients. After filtering, the data is generated through a digital-to-analog converter.

Figure 6. LabVIEW FPGA Code for an Inline Filter
NI system assurance programs are designed to make it even easier for you to own an NI system. These programs include configuration and deployment services for your NI PXI, CompactRIO, or Compact FieldPoint system. The NI Basic System Assurance Program provides a simple integration test and ensures that your system is delivered completely assembled in one box. When you configure your system with the NI Standard System Assurance Program, you can select from available NI system driver sets and application development environments to create customized, reorderable software configurations. Your system arrives fully assembled and tested in one box with your software preinstalled. When you order your system with the standard program, you also receive system-specific documentation including a bill of materials, an integration test report, a recommended maintenance plan, and frequently asked question documents. Finally, the standard program reduces the total cost of owning an NI system by providing three years of warranty coverage and calibration service. Use the online product advisors at ni.com/advisor to find a system assurance program to meet your needs.
Get answers to your technical questions using the following National Instruments resources.
While you may never need your hardware repaired, NI understands that unexpected events may lead to necessary repairs. NI offers repair services performed by highly trained technicians who quickly return your device with the guarantee that it will perform to factory specifications. For more information, visit ni.com/repair.
The NI training and certification program delivers the fastest, most certain route to increased proficiency and productivity using NI software and hardware. Training builds the skills to more efficiently develop robust, maintainable applications, while certification validates your knowledge and ability.
NI offers options for extending the standard product warranty to meet the life-cycle requirements of your project. In addition, because NI understands that your requirements may change, the extended warranty is flexible in length and easily renewed. For more information, visit ni.com/warranty.
NI offers design-in consulting and product integration assistance if you need NI products for OEM applications. For information about special pricing and services for OEM customers, visit ni.com/oem.
Our Professional Services Team is comprised of NI applications engineers, NI Consulting Services, and a worldwide National Instruments Alliance Partner program of more than 700 independent consultants and integrators. Services range from start-up assistance to turnkey system integration. Visit ni.com/alliance.
|
This section lists the specifications of the NI FlexRIO adapter module (NI 5751). Pair these specifications with the specifications listed in the NI FlexRIO FPGA Module Installation Guide and Specifications. For more information about safety and electromagnetic compatibility refer to the Read Me First: Safety and Electromagnetic Compatibility document included in your hardware kit or available at ni.com/manuals. Maximum and minimum specifications are warranted not to exceed these values within certain operating conditions and include the effects of temperature and uncertainty unless otherwise noted. Characteristic specifications are unwarranted values that are representative of an average unit operating at room temperature. Typical specifications are unwarranted values that are representative of a majority (90%) of units within certain operating conditions and include the effects of temperature and uncertainty unless otherwise noted. These specifications are characteristic at 25 °C unless otherwise noted. |
||
| Absolute Maximum Ratings | ||
|
Caution Stresses beyond those listed in this section may cause permanent damage to the adapter module. Avoid swapping the analog and digital cables because doing so will short the digital output terminals to ground. |
||
|
Analog input overload |
±2 V | |
|
External clock input |
–0.5 V to 3.5 V | |
|
Digital input |
–0.5 V to 3.5 V | |
|
Digital output current |
2 mA | |
| Analog Input (AI 0 to AI 15) | ||
| General Characteristics | ||
|
Type of connector |
VHDCI. For pinout, refer to NI 5751 Pinout—Analog Input CH 0 to 15 | |
|
Number of channels |
16 single-ended | |
|
Max input voltage swing |
2 Vpp | |
|
Input impedance |
50 Ω ±2% | |
|
Coupling |
DC coupled | |
|
ADC manufacturer part number |
AD9252, 14-bit pipelined analog-to-digital converter | |
|
Note For additional information on the AD9252, refer to the device datasheet at www.analog.com. |
||
| Specific Characteristics | ||
| NI 5751 Characteristic Frequency Response | ||
![]() |
||
| NI 5751 Characteristic Frequency Response | ||
![]() |
||
|
Bandwidth (–3 dB) |
26 MHz | |
|
DC gain error |
±2% of input | |
|
DC offset error |
±2% of FS | |
|
Crosstalk |
–75 dB at 1 MHz, –65 dB at 5 MHz, Measured on one channel with test signal applied to another channel | |
|
Signal-to-noise ratio (SNR) |
71 dB, –1 dBFS input signal, fin = 5 MHz | |
|
Spurious-free dynamic range (SFDR) |
73 dBc, –1 dBFS input signal, fin = 5 MHz | |
|
Total harmonic distortion (THD) |
73 dBc, –1 dBFS input signal, fin = 5 MHz | |
|
Average noise density |
–147 dBFS/Hz | |
| NI 5751 Characteristic Dynamic Performance, Spectrum-64 k Samples, 5.3 MHz, –1 dBFS Input Signal | ||
![]() |
||
| NI 5751 Characteristic Noise Density, Spectrum-64 k Samples | ||
![]() |
||
| Sample Clock | ||
|
Sample clock sources |
||
|
Sample clock frequency range |
30 MHz to 50 MHz 2 | |
| CLK IN | ||
| General Characteristics | ||
|
Connector |
SMB | |
|
Logic Level |
3.3 V CMOS | |
|
VIH |
2.2 V | |
|
VIL |
0.6 V | |
|
Input impedance |
> 50 kΩ | |
|
Input coupling |
DC | |
|
Duty cycle |
45% to 55% | |
| Digital Input Terminals | ||
| General Characteristics | ||
|
Number of channels |
8 | |
|
Connector |
VHDCI. For pinout, refer to NI 5751 Pinout—Digital Connector | |
|
Minimum high-level input voltage |
||
|
VIH (min) |
2.0 V | |
|
Maximum low-level input voltage |
||
|
VIL (max) |
0.8 V | |
| Digital Output Terminals | ||
| General Characteristics | ||
|
Number of channels |
8 | |
|
Connector |
VHDCI. For pinout, refer to NI 5751 Pinout—Digital Connector | |
|
Minimum high-level output voltage |
||
|
VOH (min) |
2.4 V | |
|
Maximum low-level output voltage |
||
|
VOL (max) |
0.55 V | |
|
Maximum output current |
1 mA | |
|
Minimum pulse width |
10 ns | |
|
Maximum toggle frequency |
1 MHz, All outputs toggling | |
| Hardware Block Diagram | ||
| NI 5751 Hardware Block Diagram | ||
![]() |
||
| NI 5751 FlexRIO CLIP Node Wire Descriptions | ||
| NI 5751 CLIP Node IO Descriptions | ||
|---|---|---|
| Port Name | Type | Function |
| AI A<0..7> | I16 | Data from each of the eight channels on ADC A. If you are using the NI 5751 CLIP, data is clocked out of the CLIP on IO Module Clock 0. If you are using the NI 5751 Multidevice Synchronization CLIP, data is clocked out of the CLIP on DStarA. After Initialization Done is asserted the data is valid on every clock cycle. |
| AI B<8..15> | I16 | Data from each of the eight channels on ADC B. If you are using the NI 5751 CLIP, data is clocked out of the CLIP on IO Module Clock 0. If you are using the NI 5751 Multidevice Synchronization CLIP, data is clocked out of the CLIP on DStarA. After Initialization Done is asserted the data is valid on every clock cycle. |
| DI <0..7> | Boolean | Digital Input. Refer to the Digital Input Terminals section for more information. |
| DO <0..7> | Boolean | Digital Output. Refer to the Digital Output Terminals section for more information. |
| Digital Output Enable | Boolean | Enables the digital outputs. |
| IO Module Clock 0 | FPGA Clock | The ADC sample clock. |
| Sample Clock Select | U8 |
Selects which clock is used as the ADC sample clock. When Sample Clock Select is changed, the data capture circuit is reinitialized. 3 This signal should be inside a single-cycle timed loop with a clock source of the 40 MHz onboard clock.
|
| Force Initialization | Boolean | Forces a CLIP initialization. 3 If you are using an external clock and the clock frequency changes, this signal must be manually asserted. ADC registers retain their values when Force Initialization is manually asserted. This signal should be inside a single-cycle timed loop with a clock source of the 40 MHz onboard clock. |
| Initialization Done | Boolean | When this signal is asserted, initialization 3 of the CLIP has completed. This signal should be inside a single-cycle timed loop with a clock source of the 40 MHz onboard clock. |
| ADC Error A | Boolean | When ADC Error A is asserted the width of the sampling window from ADC A has shrunk below its required value, which does not guarantee that the data can be sampled correctly. This could be caused by a noisy clock source, a damaged ADC, or an incompatible NI FlexRIO FPGA module. ADC Error A is a sticky bit and is cleared upon reinitialization. 3 |
| ADC Error B | Boolean | When ADC Error B is asserted the width of the sampling window from ADC B has shrunk below its required value, which does not guarantee that the data can be sampled correctly. This could be caused by a noisy clock source, a damaged ADC, or an incompatible NI FlexRIO FPGA module. ADC Error B is a sticky bit and is cleared upon reinitialization. 3 |
| PLL Unlocked | Boolean | Indicates that the PLL has become unlocked since the board was initialized. When the PLL is unlocked IO Mod Clock 0 is disabled. When set, PLL Unlocked is cleared upon reinitialization. 3 This signal should be inside a single-cycle timed loop with a clock source of the 40 MHz onboard clock. |
| SPI Idle 4 | Boolean | Indicates the SPI engine is idle and ready for a SPI read or write transaction. This signal should be inside a single-cycle timed loop with a clock source of the 40 MHz onboard clock. |
| SPI Device Select 4 | U8 |
Selects which ADC the SPI port will communicate with. This signal should be inside a single-cycle timed loop with a clock source of the 40 MHz onboard clock.
|
| SPI Address 4 | U8 | The address of the register in the ADC selected. This signal should be inside a single-cycle timed loop with a clock source of the 40 MHz onboard clock. |
| SPI Write Data 4 | U16 | Data to be written to the register in the ADC selected. This signal should be inside a single-cycle timed loop with a clock source of the 40 MHz onboard clock. |
| SPI Write 4 | Boolean | Begin SPI write transaction. The SPI Write signal should be inside a single-cycle timed loop with a clock source of the 40 MHz onboard clock. |
| Initialization | ||
|
During initialization, the CLIP does the following:
|
||
| Manual Initialization | ||
|
The user FPGA code must manually start initialization in the following instance:
To manually start initialization, the user FPGA code must assert Force Initialization. Note When initialization starts, the Initialization Done signal deasserts within 100 ns. Initialization Done does not assert again until initialization has completed. You can expect a delay of up to 2 seconds before Initialization Done asserts again, depending on your clock rate. If you read the Initialization Done indicator before it has had time to deassert (100 ns), you may get a false positive. |
||
| Automatic Initialization | ||
|
The CLIP performs initialization automatically in the following instances:
FPGA IO is enabled automatically when the CLIP is loaded into the FPGA. You can also programmatically enable and disable the FPGA IO from the host VI. When FPGA IO is enabled, the CLIP resets all ADC registers. Caution Do not execute user FPGA code using IO Module Clock 0 until Initialization Done is True. While Initialization Done is False, the clocks are not stable. If the user FPGA code changes the Sample Clock Select signal, the CLIP begins initialization automatically; you do not need to assert Force Initialization. Note When initialization starts, the Initialization Done signal deasserts within 100 ns. Initialization Done does not assert again until initialization has completed. You can expect a delay of up to 2 seconds before Initialization Done asserts again, depending on your clock rate. If you read the Initialization Done indicator before it has had time to deassert (100 ns), you may get a false positive. |
||
| Accessing SPI Registers | ||
|
The ADC register maps are included in the AD9252 datasheet. The following application note found on Analog Devices' Web site contains more information and SPI functionality for the AD9252: AN-877 Application Note, Interfacing to High Speed ADCs via SPI. SPI reads from the AD9252 are not supported on the NI 5751. The SPI access does not actually take effect until the software transfer bit (bit 0) of the device_update (offset 0xFF) register is written. To access a register in an ADC, complete the following steps:
|
||
| Power | ||
| Power requirements from the NI FlexRIO FPGA module | ||
|
+12 V |
200 mA, 2.4 W max | |
|
+3.3 V |
900 mA, 2.97 W max | |
|
Total power |
5.37 W | |
| Physical | ||
|
Dimensions |
12.9 × 2.0 × 12.1 cm (5.1 × 0.8 × 4.7 in.) | |
|
Weight |
284 g (10 oz) | |
|
Front panel connectors |
One SMB connector and two 68-pin VHDCI connectors | |
| Environmental | ||
| This device is intended for indoor use only. | ||
|
Operating environment |
0 °C to 55 °C, Tested in accordance with IEC-60068-2-1 and IEC-60068-2-2. | |
|
Relative humidity range |
10% to 90%, noncondensing, Tested in accordance with IEC-60068-2-56. | |
|
Altitude |
2,000 m | |
|
Pollution Degree |
2 | |
| Storage environment | ||
|
Ambient temperature range |
–20 °C to 70 °C, Tested in accordance with IEC-60068-2-1 and IEC-60068-2-2. | |
|
Relative humidity range |
5% to 95%, noncondensing, Tested in accordance with IEC-60068-2-56. | |
|
Note Clean the device with a soft, non-metallic brush. Make sure that the device is completely dry and free from contaminants before returning it to service. |
||
| Compliance and Certifications | ||
| Safety Standards | ||
|
This product is designed to meet the requirements of the following standards of safety for electrical equipment for measurement, control, and laboratory use:
Note For UL and other safety certifications, refer to the product label or the Online Product Certification section. |
||
| Electromagnetic Compatibility | ||
|
This product meets the requirements of the following EMC standards for electrical equipment for measurement, control, and laboratory use:
Note For EMC declarations and certifications, refer to the Online Product Certification section. Note When operating this product, use shielded cables and accessories. |
||
| CE Compliance | ||
| Online Product Certification | ||
| To obtain product certifications and the DoC for this product, visit ni.com/certification, search by module number or product line, and click the appropriate link in the Certification column. | ||
| 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 not only to the environment but also to NI customers. For additional environmental information, refer to the NI and the Environment 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. |
||
| Waste Electrical and Electronic Equipment (WEEE) | ||
|
EU Customers At the end of the product life cycle, all products must be sent to a WEEE recycling center. For more information about WEEE recycling centers, National Instruments WEEE initiatives, and compliance with WEEE Directive 2002/96/EC on Waste Electrical and Electronic Equipment, visit ni.com/environment/weee.htm.
|
||
![]() |
||||||||||||||
| NI 5751 Front Panel Connectors | ||||||||||||||
|
![]() |
| NI 5751 Pinout-Digital Connector |
![]() |
| NI 5751 Pinout-Analog Input CH 0 to 15 |
©2010 National Instruments. All rights reserved. CompactRIO, FieldPoint, LabVIEW, National Instruments, National Instruments Alliance Partner, NI, ni.com, and NI FlexRIO are trademarks of National Instruments. Other product and company names listed are trademarks or trade names of their respective companies. A National Instruments Alliance Partner is a business entity independent from National Instruments and has no agency, partnership, or joint-venture relationship with National Instruments.