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STLC7550 Definition and Terminology
Rev 9 21/24
5 Definition and Terminology
Data Transfer Interval The time during which data is transfered from DOUTand to
D
IN. This interval is 16 shift clocks provides by the chip.
Signal Data This refers to the input signal and all the converted
representations through the ADC channel and the DAC
channel.
Data Mode This refers to the data transfer. Since the device is
synchronous, the signal data words from the ADC channel
and to the DAC channel occur simultaneously.
Control Mode This refers to the digital control data transfer into DIN and
the register read data from D
OUT. The control mode interval
occurs when requested by hardware or software.
Frame Sync. Frame sync refers only to the falling edge of the signal which
initiates the data transfer interval. The primary frame sync
starts the Data Mode and the secondary frame sync starts
the Control Mode.
Frame Sync and Sampling
Period
The time between falling edges of successive primary frame
sync signals.
ADC Channel This term refers to all signal processing circuits between the
analog input and the digital conversion result at D
OUT.
DAC Channel This term refers to all signal processing circuits between the
digital data word applied to D
INand the differential output
analog signal available at OUT+ and OUT-pins.
OverSampling Ratio This term refer to the ratio between the master clock MCLK
corresponding to the oversampling frequency and the
sampling frequency FS.
Resolution The number of bits in the input words to the DAC, and the
output words in the ADC.
Dynamic Range The S/(N+D) with a 1kHz, -20dBr input signal and
extrapolated to full scale. Use of a small input signal reduces
the harmonic distortion components of the noise to
insignificance. Units in dB or in N
bitas explained before.
Signal-to-
(Noise+Distortion)
S/(THD+N) is the ratio of the rms of the input signal to the
rms of all other spectral components within the
measurement bandwidth (0.425 x Sampling Frequency).
Units in dB.
Crosstalk The amount of 1kHz signal present on the output of the
grounded input channel with 1kHz 0dB signal present on the
other channel. Units in dB.
Power Supply Rejection
Ratio
PSRR. The amount of 1kHz signal present on the output of
the grounded input channel with 1kHz 200mV
PPsignal
present on the power supply.
