Datasheet LTC1749 (Analog Devices) - 10
| Manufacturer | Analog Devices |
| Description | 12-Bit, 80Msps Wide Bandwidth ADC |
| Pages / Page | 20 / 10 — W U. TI I G DIAGRA. APPLICATIO S I FOR ATIO. DYNAMIC PERFORMANCE. … |
| File Format / Size | PDF / 289 Kb |
| Document Language | English |
W U. TI I G DIAGRA. APPLICATIO S I FOR ATIO. DYNAMIC PERFORMANCE. Signal-to-Noise Plus Distortion Ratio
Model Line for this Datasheet
Text Version of Document
LTC1749
W U W TI I G DIAGRA
N • ANALOG INPUT t3 t t 1 2 t0 ENC t7 t8 DATA (N – 5) DATA (N – 4) DATA DATA (N – 3) DB11 TO DB0 DB11 TO DB0 t6 CLKOUT 1749 TD t4 t5 t10 t9
U U W U APPLICATIO S I FOR ATIO DYNAMIC PERFORMANCE
where V1 is the RMS amplitude of the fundamental fre- quency and V2 through Vn are the amplitudes of the
Signal-to-Noise Plus Distortion Ratio
second through nth harmonics. The THD calculated in this The signal-to-noise plus distortion ratio [S/(N + D)] is the data sheet uses all the harmonics up to the fifth. ratio between the RMS amplitude of the fundamental input
Intermodulation Distortion
frequency and the RMS amplitude of all other frequency components at the ADC output. The output is band limited If the ADC input signal consists of more than one spectral to frequencies above DC to below half the sampling component, the ADC transfer function nonlinearity can frequency. produce intermodulation distortion (IMD) in addition to THD. IMD is the change in one sinusoidal input caused by
Signal-to-Noise Ratio
the presence of another sinusoidal input at a different The signal-to-noise ratio (SNR) is the ratio between the frequency. RMS amplitude of the fundamental input frequency and If two pure sine waves of frequencies fa and fb are applied the RMS amplitude of all other frequency components to the ADC input, nonlinearities in the ADC transfer func- except the first five harmonics and DC. tion can create distortion products at the sum and differ- ence frequencies of mfa ± nfb, where m and n = 0, 1, 2, 3,
Total Harmonic Distortion
etc. The 3rd order intermodulation products are 2fa + fb, Total harmonic distortion is the ratio of the RMS sum of all 2fb + fa, 2fa – fb and 2fb – fa. The intermodulation harmonics of the input signal to the fundamental itself. The distortion is defined as the ratio of the RMS value of either out-of-band harmonics alias into the frequency band input tone to the RMS value of the largest 3rd order between DC and half the sampling frequency. THD is intermodulation product. expressed as: V22 V32 V42 Vn2 ... THD = + + + Log 20 V1 1749f 10
W U W TI I G DIAGRA
N • ANALOG INPUT t3 t t 1 2 t0 ENC t7 t8 DATA (N – 5) DATA (N – 4) DATA DATA (N – 3) DB11 TO DB0 DB11 TO DB0 t6 CLKOUT 1749 TD t4 t5 t10 t9
U U W U APPLICATIO S I FOR ATIO DYNAMIC PERFORMANCE
where V1 is the RMS amplitude of the fundamental fre- quency and V2 through Vn are the amplitudes of the
Signal-to-Noise Plus Distortion Ratio
second through nth harmonics. The THD calculated in this The signal-to-noise plus distortion ratio [S/(N + D)] is the data sheet uses all the harmonics up to the fifth. ratio between the RMS amplitude of the fundamental input
Intermodulation Distortion
frequency and the RMS amplitude of all other frequency components at the ADC output. The output is band limited If the ADC input signal consists of more than one spectral to frequencies above DC to below half the sampling component, the ADC transfer function nonlinearity can frequency. produce intermodulation distortion (IMD) in addition to THD. IMD is the change in one sinusoidal input caused by
Signal-to-Noise Ratio
the presence of another sinusoidal input at a different The signal-to-noise ratio (SNR) is the ratio between the frequency. RMS amplitude of the fundamental input frequency and If two pure sine waves of frequencies fa and fb are applied the RMS amplitude of all other frequency components to the ADC input, nonlinearities in the ADC transfer func- except the first five harmonics and DC. tion can create distortion products at the sum and differ- ence frequencies of mfa ± nfb, where m and n = 0, 1, 2, 3,
Total Harmonic Distortion
etc. The 3rd order intermodulation products are 2fa + fb, Total harmonic distortion is the ratio of the RMS sum of all 2fb + fa, 2fa – fb and 2fb – fa. The intermodulation harmonics of the input signal to the fundamental itself. The distortion is defined as the ratio of the RMS value of either out-of-band harmonics alias into the frequency band input tone to the RMS value of the largest 3rd order between DC and half the sampling frequency. THD is intermodulation product. expressed as: V22 V32 V42 Vn2 ... THD = + + + Log 20 V1 1749f 10
