LTC1409 W UTI I G CHARACTERISTICSNote 11: The falling CONVST edge starts a conversion. If CONVST returns Note 12: Signal-to-noise ratio (SNR) is measured at 100kHz and distortion high at a critical point during the conversion it can create small errors. For is measured at 400kHz. These results are used to calculate signal-to-noise best results ensure that CONVST returns high either within 650ns after plus distortion (SINAD). conversion start or after BUSY rises. WUTYPICAL PERFORMANCE CHARACTERISTICSS/(N + D) vs Input FrequencySignal-to-Noise Ratio vsand AmplitudeInput FrequencyDistortion vs Input Frequency 80 80 0 –10 70 VIN = 0dB 70 –20 60 60 –30 50 VIN = 20dB 50 –40 40 40 –50 –60 30 30 –70 20 20 –80 3RD VIN = 60dB THD SIGNAL/(NOISE + DISTORTION) (dB) 10 SIGNAL/(NOISE + DISTORTION) (dB) 10 –90 2ND AMPLITUDE (dB BELOW THE FUNDAMENTAL) 0 0 –100 1k 10k 100k 1M 10M 1k 10k 100k 1M 10M 1k 10k 100k 1M 10M INPUT FREQUENCY (Hz) INPUT FREQUENCY (Hz) INPUT FREQUENCY (Hz) LTC1409 • TPC03 LTC1409 • TPC01 LTC1409 • TPC02 Spurious-Free Dynamic Range vs Input FrequencyIntermodulation Distortion Plot 0 0 fSAMPLE = 800kHz –10 fIN1 = 88.19580078kHz –20 f –20 IN2 = 111.9995117kHz –30 –40 –40 –50 –60 fb – fa 2fa fa + fb + fb –60 fa + 2fb 3fa AMPLITUDE (dB) –80 2fa – fb 2fb – fa –70 2fb 2fa –80 3fb –100 SPURIOUS-FREE DYNAMIC RANGE (dB) –90 –100 –120 10k 100k 1M 10M 0 50k 100k 150k 200k 250k 300k 350k 400k INPUT FREQUENCY (Hz) FREQUENCY (Hz) LTC1409 • TPC04 LTC1409 • TPC05 5