What is a Digitizer? Understanding its Applications and Key Specifications

A digitizer is a device that converts analog data into a digital format. This analog data can take many forms, including images, sound, video, documents, and other types of signals. Many digitizers include an attached LCD screen.

Popular digitizer manufacturers include Applicos, Keysight, NI (National Instruments), SP Devices, and Spectrum Gmbh.

Common Applications of Digitizers

Digitizers find use in a wide variety of applications:

• Semiconductor Testing: Used for analyzing and characterizing semiconductor devices.
• Non-Destructive Testing (NDT): Applications like ultrasound utilize digitizers for image processing and analysis.
• Medical Imaging: Crucial components in systems like MRI and CT scanners for capturing and processing image data.
• Radar: Used in radar systems for signal acquisition and processing.
• SDR (Software Defined Radio): Enabling flexible radio systems through digital signal processing.
• Video Signal Analysis: Examining and analyzing video signals for various purposes.
• Cable Fault Testing: Locating and diagnosing faults in cables using signal analysis.
• Communication Protocol Analysis: Analyzing communication signals to ensure proper protocol implementation.

Digitizer Architecture

A digitizer is essentially a collection of multiple Analog-to-Digital Converters (ADCs) combined with additional features, such as buffer memory and programming capabilities. Each channel of the digitizer is equipped with its own ADC module.

The digitizer acquires data from these multiple channels, stores it temporarily, and then transmits it for further processing.

Modern Digitizer Interfaces

Modern digitizers often incorporate a variety of built-in interfaces to facilitate integration into different systems:

• AXIe
• cPCI
• LXI
• MTCA
• PCI
• PCIe
• PXI
• VME-bus
• VXI and VPX (specifically for test system integration)

Key Specifications for Buying a Digitizer

When selecting a digitizer, consider the following specifications:

• Bandwidth: The range of frequencies the digitizer can accurately capture.
• Sampling Rate: How many samples per second the digitizer can acquire.
• Resolution and Dynamic Range: These determine the precision and range of signals the digitizer can measure.
• On-board Memory: The amount of memory available for storing acquired data.

Digitizer Manufacturers

Here are some popular digitizer manufacturers and examples of their products:

• NI (National Instruments)

  • Model No: NIPCIe-5170R reconfigurable digitizer/oscilloscope
  • Features: Incorporates FPGAs for user reconfiguration and programming using LabVIEW.

• Keysight

  • Model No: M9703A wideband AXIe Digitizer
  • Features: 8 channels, DC to 2 GHz frequency input, 12-bit resolution, 3.2 GSPS sampling rate, on-board FPGAs for processing.

• Applicos

  • Model No: PD24222 (24-bit digitizer)
  • Features: Dual channel, differential inputs, 32mV to 10V p-p Input, programmable DC offset, LabVIEW and LabWindows support.

• Spectrum Gmbh

  • Model Nos: M4i.22xx-x8 series digitizer cards
  • Features: 1, 2, or 4 channels per card, 5 GSPS sampling rate, 1 GHz bandwidth, 4 GB onboard memory, PCIe x8 Gen2 interface. Spectrum Gmbh offers a variety of other digitizer models as well.

• SP Devices

  • Model No: ADQ1600
  • Features: 14-bit resolution, 1.6 GSPS sampling rate, onboard FPGA for real-time signal processing.

Digitizer, DAQ, and Digital Oscilloscope: What’s the Difference?

Refer to resources that compare digitizers, DAQs (Data Acquisition Systems), and digital oscilloscopes to understand the distinctions between these three digital systems based on various factors.