L-502 Multifunctional ADC/DAC board with PCIe (PCI express) interface

Multifunctional ADC/DAC board with PCIe (PCI express) interface
  • ADC: 16 bits / 2 MHz
  • Input channels: 16 differential or 32 with "common ground"
  • Blackfin digital signal processor with 32 MB of RAM (optional)
  • Digital inputs/outputs: 18/16
  • Synchronous digital input: 2 MHz (18 lines) and 1 MHz synchronous digital output (16 lines)
  • Synchronization of several L-502 in one system unit
  • PCI Express x1 rev.1.0
  • Two-channel DAC 16 bits, 1 MHz per channel (optional)
  • Galvanic isolation from the computer (optional)

Universal I/O board for analog and digital signals to PC via PCI Express interface with the possibility of their digital processing in real time.

As an option, it is possible to install a two-channel 16-bit DAC with the possibility of synchronous output with a frequency of up to 1 MHz per channel.

ADC channels switching during multichannel data acquisition mode is automatic, with arbitrary channel sampling order, with a given measurement sub-range and averaging factor of ADC samples for each channel.

Installed in L-502-P powerful signal processor Blackfin (ADSP-BF523), running at a sampling rate of 530 MHz with a connected SDRAM 32 MB, allows a low-level programmer to implement his own algorithms that work in real time and are not dependent on the operating system. Almost all Blackfin performance (especially effective at DSP tasks) is given to user processing tasks, since all Blackfin interface transfers are implemented by DMA and Blackfin memory is directly displayed in PC memory. But, at the same time, the lack of Blackfin in the L-502-X does not interfere with the implementation of real-time algorithms using PC.

The high-tech architecture of the L-502 also uses the CPLD of Max II family and FPGA of Cyclone IV family.

The architecture of the L-502 was developed in the new E-502 external module with USB&Ethernet, software compatible with L-502. The same Blackfin software can be used in L-502 and E-502 . The architecture of the L-502 and E-502 at the Blackfin level is identical (there are minor differences, which are described in the E-502 manual).

L-502 high-speed synchronous data I/O has a wide range of applications. For example, based on the L-502, image input systems from CCD sensors with sensor control from L-502 can be built.

Number of channels 16 differential or 32 with "common ground"
Resolution 16 bits
Effective resolution (for a sinusoidal signal of 10 kHz / 2 V peak-peak, the conversion frequency is 400 kHz) 15,0 bits (corresponds to SINAD = 92 dB)
Input impedance (at single-channel mode)
  • Relative to AGND - not less than 20 MOhm
  • Differential - not less than 40 MOhm
Input signal measuring sub-ranges ±10 V, ±5 V, ±2 V, ±1 V, ±0,5 V, ±0,2 V
Maximum conversion frequency 2 MHz
(1.5 MHz when synchronizing the conversion frequency from another L-502 board)
The main error (referred to the range) of the DC voltage measurement ±0,05 %
  • Internal
  • By external synchro-signal
  • Synchronization of multiple L-502
Inputs protection ±15 V
Common-mode rejection ratio 50 Hz with amplitude 1 V in differential mode (by subbands)
  •  77 dB (±10 V)
  •  83 dB (±5 В)
  •  90 dB (±2 V)
  •  92 dB (± 1 V)
  •  92 dB (± 0,5 V)
  •  92 dB (± 0,2 V)
The intrinsic input noise of ADC at the shorted input, depending on the sub-band of ADC and the averaging factor of the samples (K average) for each channel.
Sampling frequency К average

ADC sub-range, V

±10  ±5  ±2  ±1  ±0,5  ±0,2 

Typical value of noise level, brought to the input of ADC, μV

2 MHz 1 309 157 50 37 22 18
400 kHz 5 127 56 28 16 12 8
50 kHz 20 62 27 13 8 6 4
10 kHz 128 40 25 12 7 5 4
Inter-channel interference, dB
Resistance of the signal source 
(in the channel in which the interchannel interference is measured)

Channel sampling time, μs (with averaging coefficient equal to 1) or channel setup time, μs

0,5 1,0 2,0 4,0 8,0 16,0

Inter-channel interference, dB
(the signal from the previous channel in the order of interrogation)

0-50 Ohm -65 -78 -82 -82 -82 -82
Digital signal processor (option)
Type Blackfin ADSP-BF523
Sampling rate 530 MHz
RAM 32 MB (SDRAM, 16 bits; 132,5 MHz)
Program interface with ADSP-BF523 Independent, via HOST DMA of ADSP-BF523 processor
The main interface for peripherals (ADC, DAC, digital I/O) SPORT0, >120 Mbps, duplex
Galvanic isolation (option)
Galvanic isolation boundaries Between all the circuits that ends to the contacts of the signal connectors and PC circuits. The metal housing of the DRB-37M connector is not galvanically isolated from the PC.
Test voltage of galvanic isolation 500 V for 1 min.
L-502 modifications, in which galvanic isolation is available L-502-P-G, L-502-P-G-D, L-502-X-G, L-502-X-G-D
DAC (option)
Number of voltage outputs with common ground 2
Frequency of output in synchronous mode 1 MHz per channel
Output modes Synchronous (streaming) or asynchronous
Output range ±5 V
Operating range of output currents 0-10 mA
Digital inputs
Total number of digital general-purpose inputs 18 (two of them can be used for synchronization)
Data entry modes Synchronous, asynchronous
Pull-up resistors to a high logic level Yes
Maximum speed in synchronous mode 2 MHz
Recommended operating voltage range 0 …+5,5 V
High-impedance state with power off Yes
Maximum input current with power off 10 μA
Own input current in operating mode with software-activated pull-up resistors 10 μA
The resistance of pull-up resistors 2.2 kOhm relative to +3.3 V (pull-up resistors are programmatically switched-on for groups of inputs)
Digital outputs
Total number of TTL-compatible digital outputs 16
Control of the third state of outputs Yes
Data output modes Synchronous, asynchronous
Maximum speed in synchronous mode 1 Msamples/s
Maximum permissible current in the load circuit 20 mA
Recommended current in the load circuit Not more than 8 mA
Logical "1" level without load output +3,3 V
Logical "0" level without load output 0…+0,1 V
Output resistance, typical value 110 Ohm
Maximum leakage current in operating mode in high-impedance state ±1 μA
High-impedance state with power off No
Inter-module synchronization
Topology of multimodule connections over synchronization lines Sequence (inside one PC system unit)
Maximum number of synchronized L-502 modules in sequence synchronization scheme Equal to the number of PCIe slots in the PC motherboard
Maximum length of inter-module synchronization cable 40 cm (only to the neighboring PCIe slot)
Number of inter-module synchronization lines 2 twisted pairs
Interface to computer
Standard PCIe  x1  rev. 1.0  (the board is compatible with the PCI Express slot of the motherboard of any bandwidth: x1, x2, x4, x8, x12, x16, x32).
Maximum data transfer rate for PCIe 200 MB/s, duplex (physical throughput of the PCIe controller)
Resolution of the L-502 data sample for PCIe 32 bits
DMA support at BUS MASTER mode for PCIe Yes
Design characteristics
Design PCI Express CARD  x1  standard height, with bracket, less than half length (HALF LENGTH), in accordance with PCI Express Card Electromechanical Specification rev.2.0. 
Requires one PCI Express slot.
Overall dimensions of the PCB (length x height) 136 x 101 mm
Environmental conditions
General requirements L-502 is designed for use in closed premises in accordance with the requirements of National Standart 22261 (group 3) with an extended range of operating temperatures.
Normal conditions
Ambient temperature (+25±5)°C
Relative humidity 30…80%
Atmosphere pressur 630…800 mm hg. art.
Operating conditions
Ambient temperature +5… + 55°C
Relative humidity Up to 90% at +25°C
Storage conditions
Ambient temperature +0… + 40°C
Relative humidity Up to 80% at +25°C without condensation
Other The absence of dust, acid vapors, alkalis, and corrosive gases in the air
Transportation conditions
Ambient temperature -25… +55°C
Relative humidity Not more than 95% at the temperature of +25°C
Other All kinds of transport provided protection against direct atmospheric precipitation
External circuits power supply
Power supply outputs for external analog and digital circuit +15 V, -15 V, +3,3 V. The maximum currents taken from the outputs are selected by the criterion of not exceeding the maximum load power according to the methodology in Manual.
Maximum power load, taken from all L-502 outputs
For L-502-X-X-D (with DAC) 0,4 W
For L-502-X-X (without DAC) 0,8 W

Signal connectors

Hardware description, assignment and connection of signals is given in the User's Guide.

Notation system

Note on technically possible modifications of L-502: When ordering from 40-50 pcs. it is possible to produce a purely digital modification of L-502 at a reduced price without analog I/O ADC/DAC. On interest in such a modification of L-502, please contact Sales Department.

  • L-502-X-X
    board with no galvanic isolation, no DAC, no processor
  • L-502-X-X-D
    board with DAC, no galvanic isolation, no processor
  • L-502-X-G
    board with galvanic isolation, no DAC, no processor
  • L-502-X-G-D
    board with galvanic isolation, with DAC, no processor
  • L-502-P-G
    board with galvanic isolation, with processor, no DAC
  • L-502-P-G-D
    board with galvanic isolation, with processor, with DAC


  • l-502_users_guide_en.pdf (filesize: 1 349 400 bytes, date: 27.02.2018)

    L-502 PCI-Express board User's Guide.

  • x502api_en.pdf (filesize: 1 059 110 bytes, date: 16.04.2018)

    Programmer's Guide for L502 and E502 modules.

LGraph2 software package

  • lgraph2.zip (filesize: 26 786 707 bytes, date: 11.10.2021)

    LGraph2 is a free multi-channel data recorder for Windows. Version 2.35.20 provides the possibility of simultaneous data visualization and recording from the ADCs: L-502, L-780M, L-783, L-791, E-502, E14-140, E14-140M, E14-440, E-154, E20-10, LTR11, LTR114, LTR27, LTR212, LTR216, LTR22, LTR24, LTR25, LTR51. It requires an updated version of the LComp driver (from version 01.04.2010) and ltrserver (no lower than

Software for Windows

  • lpcie_setup.exe (filesize: 11 084 264 bytes, date: 01.11.2021)

    L-CARD L502/E502 SDK. Version 1.1.21. It includes driver, libraries, files for software development and programming examples for L-CARD L502 and E502 modules for Windows (starting with Windows XP SP3 and higher, including 64-bit versions).

  • x502studio.zip (filesize: 11 632 368 bytes, date: 03.09.2020)

    Demonstration software for E-502 and L-502 modules


Phone: +7 (495) 785-95-19
Fax: +7 (495) 785-95-14

Sales department: en@lcard.ru
Technical support: en@lcard.ru

5 Varshavskoye shosse, corp. 4, build. 2
Moscow 117105
Russian Federation

Send a request

Contact us

About us

More than 3,000 customers worldwide are already using L-CARD electronic equipment for a wide range of research and industrial applications. We are glad to help you at any stage of creating an electronic product: from development and production to post-warranty support.



We are looking for regional distributors providing delivery services and comprehensive after-sales support. If you want to join L-CARD distribution network please contact us.