CSE-8225 Analog to Digital Converter

Very Low Noise, Highly Configurable, 8-Channel Analog to Digital Converter

Designed with configurability and customization in mind, the Colmek CSE-8225 board offers the latest analog to digital functionality.

The CSE-8225 analog-to-digital converter provides eight channels of 24-bit Delta-Sigma Analog-to-Digital Conversion with differential inputs and a maximum input range of +/-5V at unity gain on a full length PCI card. Linking 4 cards together allows for 32 fully differential input channels per system.

The configurable front-end of the CSE-8225 provides the user with a flexible solution for a wide range of applications. The gain for each channel can be individually set in a range of 1/4 to 4096 in steps of 2. Each channel also has configurable high pass and low pass filtering stages.

The CSE-8225 provides compatibility with current popular software environments and allows users to safely and simply expand their existing hardware and software systems. The CSE-8225 is supplied with drivers for Windows 2000, XP and Vista as well as distributions of Linux based on the v2.6 kernel. RTOS and general purpose drivers are available on request.

The supplied driver automatically detects and initializes all cards installed in a system, providing a single interface to access their functionality. The efficient software interface minimizes configuration errors and speeds the integration process.

If your application demands a custom approach, Colmek engineers are at the ready. Our staff has the ability to design an acquisition package which meets your most demanding requirements. From rapid prototyping and low volume production runs to larger scale builds, our responsiveness is a benefit to any customer needing an immediate data acquisition solution.


  • 8 Channels Per Board
  • 24-bit Resolution
  • Variable Sample Rate/FIR Decimation
  • Programmable high-pass and low-pass filtering
  • Low Noise
  • Up to 128k Sample/s Sampling Rate
  • Wide Range Programmable Gain
  • Standard full length PCI form factor
  • Low noise, high accuracy amplifier sections
  • Programmable gain from ΒΌ to 4096 in steps of 2
  • High gain accuracy of +/-0.05 dB over the entire gain range
  • Programmable analog high pass filtering
  • Programmable low pass digital filtering and decimation
  • Up to 128k sample/sec on 8 channels per board
  • Multi-board operation for up to 32 simultaneously sampled channels
  • Bus Mastering PCI Interface

Tech Specs

  • Noise, Distortion and Crosstalk

    • Equivalent noise density: -156 dBV/rt. Hz maximum at 10 kHz RTI at maximum gain (16nV/rt. Hz), -120 dBV/rt. Hz maximum at 10 kHz RTO at minimum gain (1 V/rt. Hz)
    • Harmonic distortion: 0.01% maximum at gains < 256, 0.1% maximum at all gains
    • Ch.-ch. crosstalk: -100 dB at 1 kHz

  • Input Amplifier

    • Input configuration: Differential, AC coupled
    • Input impedance: 1 Mohm per leg (2 Mohm differential)
    • Input voltage at X1 gain: +/- 5 Vpk
    • Maximum safe voltage: +/- 12.5 Vpk
    • CMRR: 70 dB minimum at 1 kHz
    • Gain settings: to 4096 in steps of 2 (-12.04 dB to 72.25 dB in 6.02 dB increments)
    • Gain accuracy: +-0.05 dB (0.6%)
    • DC offset (50, 2kHz out): 20mV equivalent RTO

  • High-Pass Filtering

    • Input AC coupling: Single-pole at 1 Hz (always present)
    • Additional filter: Single-pole 50 Hz or 2 kHz high-pass that can be by passed
    • Corner frequency accuracy: 2%

  • Low-Pass Filtering

    • Digital decimation filtering: Programmable linear-phase low-pass; Corresponds to decimation rates of 1, 2, or 4; Passband is 45% of output sample rate with < 0.001dB ripple; Greater than 96dB stopband attenuation
    • Analog anti-aliasing: 3 pole anti-aliasing filter designed to minimize group delay and amplitude variation in passband

  • Digitization

    • Number of channels: 8 per board with simultaneous sampling
    • Sampling rate: Programmable 128KHz, 64KHz, 32KHz
    • Number of bits: 24bit 2s complement
    • Oversampling ratio: 64:1
    • Usable bandwidth: -3dB at 49% of output sample rate

  • Clock

    • Source: Internal or external, software selectable
    • Frequency: 33.5544 MHz.
    • Card-card sync.: Up to four cards can be linked for 32 simultaneous sampled channels

  • PCI

    • Card format: Full sized PCI (other formats available on request)
    • PCI bus format: PCI 2.1 32-Bit, 33 MHz, 3.3/5V signaling
    • Data transfer format: 32-bit packed mode
    • Transfer mechanism: Bus mastering DMA
    • PCI bridge: Bridge core on Spartan 3E FPGA
    • Estimated power: 20 W from +3.3V, +5V, and +/- 12V supplies

  • Software Provided

    • Supported Operating System: Microsoft Windows 2000, Windows XP, Windows Vista, Linux (2.6 kernels), Other
    • Driver Functions: Standard character device driver with IOCTLs for control and configuration

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