Datasheet

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DEFINITION OF SPECIFICATIONS
Analog Bandwidth
Aperture Delay
Aperture Uncertainty (Jitter)
Clock Pulse Width/Duty Cycle
Maximum Conversion Rate
Minimum Conversion Rate
Differential Nonlinearity (DNL)
Integral Nonlinearity (INL)
Gain Error
Offset Error
Temperature Drift
ADS6145, ADS6144
ADS6143, ADS6142
SLWS198B – JULY 2007 – REVISED MARCH 2008
The analog input frequency at which the power of the fundamental is reduced by 3 dB with respect to the low
frequency value.
The delay in time between the rising edge of the input sampling clock and the actual time at which the sampling
occurs.
The sample-to-sample variation in aperture delay.
The duty cycle of a clock signal is the ratio of the time the clock signal remains at a logic high (clock pulse width)
to the period of the clock signal. Duty cycle is typically expressed as a percentage. A perfect differential
sine-wave clock results in a 50% duty cycle.
The maximum sampling rate at which certified operation is given. All parametric testing is performed at this
sampling rate unless otherwise noted.
The minimum sampling rate at which the ADC functions.
An ideal ADC exhibits code transitions at analog input values spaced exactly 1 LSB apart. The DNL is the
deviation of any single step from this ideal value, measured in units of LSBs.
The INL is the deviation of the ADC ’ s transfer function from a best fit line determined by a least squares curve fit
of that transfer function, measured in units of LSBs.
The gain error is the deviation of the ADC ’ s actual input full-scale range from its ideal value. The gain error is
given as a percentage of the ideal input full-scale range.
The offset error is the difference, given in number of LSBs, between the ADC ’ s actual average idle channel
output code and the ideal average idle channel output code. This quantity is often mapped into mV.
The temperature drift coefficient (with respect to gain error and offset error) specifies the change per degree
Celsius of the parameter from T
MIN
to T
MAX
. It is calculated by dividing the maximum deviation of the parameter
across the T
MIN
to T
MAX
range by the difference T
MAX
– T
MIN
.
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