This reference design shows the ability of the high-speed amplifier, LMH6554, to perform single-ended to differential conversion to drive high-speed analog-to-digital converters (ADCs) while maintaining excellent noise and distortion performance. Performance versus input frequency is shown for both AC and DC coupled applications while interfaced to the ADS4449 quad, 250-MSPS, 14-bit ADC. 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.
- High-speed single-ended to differential conversion while maintain excellent performance
- System performance results for LMH6554 driving ADS4449
- SFDR > 82 dBFs, SNR > 71 dBFS in first Nyquist zone
- SFDR > 80 dBFs, SNR > 68 dBFS in second Nyquist zone
- Examples of both AC and DC coupled interfaces
- Demonstrates anti-aliasing filter design and performance gains
- Amplifier power supply design considerations for best performance are discussed