Noise spectra of TMS ADC channels with a 10MHz sinewave signal

The TMS PUPE modules each have 9 input channels. The plots are named as Bxx_Cn, where 'xx' is the PUPE serial number in hexadecimal and 'n' is the channel number, from 0 to 8. Each channel is a 14 bit 125 MS/s LTC2255 ADC. (See the LTS2255 Datasheet .) The LTC2255 has an SNR of 72 dB, so the noise floor of the plots should ideally be at -72-10*log(4096)=-108 dBFS.

Conditions:

• Input signal: 10MHz sine @ +12 dBm. (From a Wenzel ultra-low- noise oscillator.)
• Record length: 8192 samples. (Binwidth=15.259 kHz.)
• Vertical scale in dBFS.
• Blackman-Harris window, normalized to unit integral.