www.ti.com

THD + 10log10

P

S

P

D

(3)

ADS5440

SLAS467A – JULY 2005 – REVISED DECEMBER 2005

DEFINITION OF SPECIFICATIONS (continued)

Effective Resolution Bandwidth The highest input frequency where the SNR (dB) is dropped by 3 dB for a full-scale input

amplitude.

Total Harmonic Distortion (THD) THD is the ratio of the power of the fundamental (PS) to the power of the first five

harmonics (PD).

THD is typically given in units of dBc (dB to carrier).

Two-Tone Intermodulation Distortion IMD3 is the ratio of the power of the fundamental (at frequencies f1, f2) to the power

of the worst spectral component at either frequency 2f1– f2 or 2f2– f1). IMD3 is either given in units of dBc (dB

to carrier) when the absolute power of the fundamental is used as the reference or dBFS (dB to full scale)

when the power of the fundamental is extrapolated to the converter’s full-scale range.

9

Submit Documentation Feedback