TIDA-00094 Reference Design

Texas Instruments

Quad-Channel 250-Msps Digitizer with Variable Gain Amplifier Reference Design


This reference design shows a quad channel: 14-bit: 250-Msps digitizer with wide input range using the LMH6881 programmable differential amplifier and ADS4449 quad-channel: 14-bit: 250-Msps ADC. This combination allows an input voltage range of approximately 1 Vpp to 100 uVpp (4 dBm to -75 dBm) while maintaining a minimum SNR of 6 dB. Performance versus input frequency is shown for both AC and DC coupled applications. Various options for common-mode voltages: power supplies: and interfaces are discussed and measured to meet the requirements of a variety of applications. Anti-aliasing filter examples are shown along with the performance improvements that they provide.

  • Gain range of 6-dB to 26-dB allows wide input voltage range of 100 uVpp to 1 VppAllows single-ended or differential input sourceSFDR > 77 dBFs: SNR > 71 dBFSExamples of both AC and DC coupled interfacesDemonstrates anti-aliasing filter design and performance gainsCommon mode voltage considerations for best performance are discussed
  • Digital multimeter (DMM)
Product Categories
  • Data converters

End Equipment Reference Diagrams


Part Number Name Companion Part
ADS4449 ADS4449 Buy Datasheet
LMH6881 LMH6881 Buy Datasheet
LMH6882 LMH6882 Buy Datasheet
TPS2400 TPS2400 Buy Datasheet
TPS62420 TPS62420 Buy Datasheet
TPS7A8001 TPS7A8001 Buy Datasheet

Bill Of Materials

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Test Data

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Other Documents

Title Updated Type Size (KB)
TIDA-00094 BOM 07 Apr 2015 PDF 305
TIDA-00094 Schematic and Block Diagram 07 Apr 2015 PDF 179