Quad-Channel 250-Msps Digitizer with Variable Gain Amplifier Reference Design
TIDA-00094
This product has been released to the market and is available for purchase. For some products, newer alternatives may be available.
This product has been released to the market and is available for purchase. For some products, newer alternatives may be available.
See the Important Notice and Disclaimer covering reference designs and other TI resources.
Description
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.
Features
- Gain range of 6-dB to 26-dB allows wide input voltage range of 100 uVpp to 1 Vpp
- Allows single-ended or differential input source
- SFDR > 77 dBFs, SNR > 71 dBFS
- Examples of both AC and DC coupled interfaces
- Demonstrates anti-aliasing filter design and performance gains
- Common mode voltage considerations for best performance are discussed
See the Important Notice and Disclaimer covering reference designs and other TI resources.
