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Neptune-V6 (2 10-bit ADC)
  • Overview
  • Features & Benefits
  • Details
  • Performance Specifications


The QuiXilica Neptune-V6 VME / VXS is a 6U ANSI / VITA 41 (VXS) compliant dual channel high-speed digitizer board combining high density FPGA processing with two 10-bit ADC input channels performing at up to 2.2 GSPS (Gigasamples per second).  

QuiXilica Neptune-V6 VME / VXS
2 x 2.2 GSPS x 10-bit

By employing three Xilinx Virtex-6 FPGAs, Tekmicro’s Neptune-V6 combines high resolution wideband signal acquisition and generation with the onboard high density FPGA processing for a range of radar and Electronic Warfare applications such as target generation, jamming, and CM / CCM techniques. The result is a single slot solution that utilizes the latest ADC technology, supports advanced signal processing of up to 8+ GB/s of digitized data, and forwards the results through VME, VXS or front panel connection via SFP+ or CXP to the next processing stage.

Neptune-V6 features high bandwidth, low latency interconnect paths between each of its FPGAs.   These have been carefully specified to ensure that data from all ADC inputs can be routed to the appropriate FPGA to meet the application processing requirements.   The ADCs are organized as two independent boards each with their own clock and trigger inputs. However, a single clock and a single trigger input may be used for both channels on a single board. Synchronization of multiple boards is done using an external trigger signal. This offers significant throughput advantages for a range of advanced processing algorithms including coherent multi-channel algorithms found in applications such as direction finding, Space Time Adaptive Processing (STAP) radar, EW, ELINT and Synthetic Aperture Radar (SAR) image formation.

The Neptune-V6 is available for a wide range of operating environments including commercial grade, rugged air cooled, and conduction cooled to support deployed applications such as unmanned airborne, naval and ground vehicles. For more details, see Tekmicro’s Ruggedization Data Sheet.

In addition to Neptune-V6, Tekmicro offers a broad range of Xilinx Virtex-6 based streaming I/O and FPGA processing solutions for both analog and digital I/O in a range of form factors.




Two 10-bit ADC inputs at up to 2.2 GSPS each

Multichannel inputs in a single slot

Sample accurate synchronization across multiple boards.

Supports high channel count applications such as beam steering with up to 144 channels in a single VXS chassis

Single or dual / independent front panel clock inputs Flexible clock distribution

Twelve fiber optic interfaces running at up to 6.4 Gb/s using CXP front panel connection

Flexible data movement across the front panel for use in standard VME environments

One SFP port for Gigabit Ethernet connectivity

Network access and data movement to FPGSs via on-board Gigabit Ethernet switch

Dual 4x full duplex VXS links and 2 full duplex VITA 41.6 ethernet link

Enhanced VXS capability

Three large pin count (1759 pin package) Xilinx Virtex®-6 devices available per board (LX240, SX315, or SX475). other configurations available

Matched FPGA processing and analog data bandwidth for dense channel count systems 

5 GB DDR3 SDRAM Memory

Large memory resources for application flexibility

Two fully independent banks of (72 Mb/bank) QDRII+ memory on backend FPGA  

Advanced temperature and current monitoring

Protection from damage and usable in customer applications

Comprehensive developer’s kit provided including FPGA interface cores, QuiXstart FPGA utilities, software and reference designs Faster application development

Convection or conduction cooled options

Ruggedization designed in for demanding deployed applications


Two channels of up to 2.2 GSPS, 10-bit analog to digital conversion using the e2v AT84AS008 are possible.  Standard input is AC coupled singled-ended, with differential available as a factory build option.  Full scale input level is -2 dBm into 50 Ω single-ended, -5 dBm differential.  Control functions on the ADCs, such as sampling point adjustment and gain adjustment can be accessed from user FPGAs through a two-wire I2C compatible interface.

Virtex-6 FPGAs

Xilinx Virtex-6 FPGAs are the heart of the Neptune-V6. The FPGAs interface between the ADC’s, memory and I/O resources to provide a platform for implementing high performance real time processing. The Neptune-V6 is configured with three high pin count Xilinx Virtex-6 devices (LX240, SX315, or SX475) per board. Other device types can be used optionally or mixed for custom configurations. All FPGAs are interconnected by wide parallel LVDS busses and via high speed Aurora serial links using the Xilinx GTX transceivers.

Front Panel High Speed Serial I/O

One 12-fiber CXP site is provided on the front panel for standard protocols such as Gigabit Ethernet or Serial FPDP (ANSI VITA 17.1 & 17.2). CXP modules and breakout cables are available optionally for flexible I/O capability.

Onboard Gigabit Ethernet Networking and Switching

An onboard Gigabit Ethernet Switch connected to each FPGA supports routing of control plane signaling and minimizes FPGA involvement for data distribution/forwarding between FPGAs. A dedicated SFP port which supports both fiber and copper 1000 baseT ethernet connections is available to connect to an outside network.

VXS Backplane High Speed Serial I/O

The Neptune-V6 can be used as a VITA 41.0 payload card. Up to eight high speed serial links of up to 3.125 Gb/s full duplex data rates are supported via VITA 41.0 MultiGig RT2 P0 connector. Custom or standard communication protocols can be run over these links by providing appropriate firmware in the FPGA.

High Speed Parallel LVDS Interconnectivity 

All FPGAs are also interconnected with a number of LVDS pairs for optimized data transfer as the block diagram shows.

QuiXstart FPGA Configuration

A number of options are available for configuring the FPGA on the Neptune-V6. A JTAG connection is available to allow users to configure the FPGA via standard Xilinx development tools. Onboard flash is available and can configure the FPGA on power up. Tekmicro’s QuiXstart tool supports flexible configuration of the FPGA through a Gigabit Ethernet link from a remote server after a power up or reset event.


Two Trigger inputs are provided on the front panel to allow the hardware to be employed in a variety of radar and electronic warfare scenarios. Each trigger input is differential, supporting LVDS and LVPECL (as a build option).  One trigger input is used for the ADC channel 0 and the other is used for the ADC channel 1.   The triggers are sampled at the ADC clock rates, respectively, providing sample-accurate synchronization both within a single Neptune-V6 card and across multiple cards in a system.


One clock input serves one ADC channel, and a second clock input serves the other channel, or both analog I/O channels may be clocked from a single clock input (factory build option). The minimum input clock level is -6 dBm into 50 Ω.


The Neptune-V6 has two independent banks of onboard DDR3 SDRAM for each FPGA.  The front end FPGAs have two 1 GB banks, each with throughput of 6.4 GB/s, while the back end FPGA has two 512 MB banks, each with throughput of 3.2 GB/s.  The total memory capacity is 5 GB with aggregate throughput of 32 GB/s across six banks.  All DDR3 memory banks are clocked at 400 MHz for an 800 MT/s transfer rate. In addition, there are two fully independent banks of QDRII+ SRAM memory for the back end FPGA. Each QDRII+ device has a 72 Mbit capacity (144 Mbit total) supported by an 18-bit data bus per bank.

GPIO Connections

For general purpose I/O signals, the Neptune-V6 can be accessed via the P2 connector and there is also an SSMC connector on the front panel which can be used for such things as a GPS signal, etc.

System Monitoring / Damage Protection

The Neptune-V6 includes facilities to monitor current and temperature at various points on the board. Current monitoring of all main power rails is available through the use of a Spartan-6 FPGA.  Die temperature monitoring of the three FPGAs and temperature monitoring of three locations on the PCB is also available. This allows a first level of protection when the Neptune-V6 is operating in different environmental scenarios. The output from the sensors is available to the user’s FPGA firmware applications, to allow the application to adapt to changes in environmental conditions. The Neptune-V6 also uses the system monitoring sensors to implement a system protection mechanism which will, independently of the user’s application, prevent excessive current or temperature from damaging the board.


Quantity: 2
Connector: 1 or 2 via front panel SMA 
Sampling Rate: up to 2.2 GSPS
Resolution: 10-bits
Type: e2v AT84AS008
Bandwidth: 3.3 GHz 

Front Panel Trigger Input

Quantity: 1 or 2 via front panel SSMC connectors
Type: LVDS Termination: LVDS 100 Ω differential terminated. (LVPECL as factory build option)
Modes: Independent or common input (factory build option)


Quantity: 1 or 2 via front panel SSMC connectors
Type: Single ended 50 Ω terminated
Input Power Range: 5 dBm (min) to 10 dBm (max) 
Modes: Independent or master/slave input (factory build option)

Network Interface

Front panel SFP for fiber or copper Gigabit Ethernet
VITA 41.6 P0 interface for 1000 BASE-KX Gigabit Ethernet
Onboard Gigabit Ethernet switch


Access to Virtex-6 FPGAs is available via custom JTAG cable assembly that interfaces with the standard Xilinx JTAG programming cable.


DDR3 SDRAM (2 fully independent banks per FPGA)
Size: 1 GB per front end bank, 512 GB total per back end bank
Bus Width: 64-bits per front end bank, 32-bits per back end bank
Speed: 400 MHz clock rate, 800 MT/s

QDRII + SRAM (2 fully independent banks for backend FPGA)
Size: 72Mbits per backend bank (144Mbits total)
Bus Width: 18-bits per bank
Speed: Up to 500MHz clock rate

Backplane I/O

VME Interface: 
V6A - master, slave, A32:D32, A32:BLT, A32:MBLT, A32:2eSST
V6D - slave only, A32:D32, A32:BLT16
VXS Interface: P0 connector supports 8X high speed serial links on the backplane
GPIO Interface: P2 connector
Rear Transition Module (Optional): For rear access to the board, a Rear Transition Module is available that provides connections for GPIO connections, network access, PPS and trigger signals

Front Panel I/O

Gigabit Ethernet via SFP+
CXP supporting 12 fiber optic at up to 6.4 Gb/s per link


Standard ANSI / VITA 1.1-1997 (R2003) VMEbus board, 6U x  4HP, single 0.8” slot
Optional VXS P0 connector for backplane I/O


+5v, +3.3V, +12V from backplane.  Power consumption is dependent on customer application.  Power estimation Model is provided as part of the Developers Kit.


Contact factory for additional performance details.