THS1050

10-BIT 50 MSPS IF SAMPLING COMMUNICATIONS

ANALOG-TO-DIGITAL CONVERTER

SLAS278 – APRIL 2000

6

POST OFFICE BOX 655303

definitions of specifications

analog bandwidth

The analog input frequency at which the spectral power of the fundamental frequency of a large input signal

is reduced by 3 dB.

aperture delay

The delay between the 50% point of the rising edge of the clock and the instant at which the analog input is

sampled.

aperture uncertainity (jitter)

The sample-to-sample variation in aperture delay

differential nonlinearity

The average deviation of any output code from the ideal width of 1 LSB.

clock pulse width/duty cycle

Pulse width high is the minimum amount of time that the clock pulse should be left in logic 1 state to achieve

rated performance; pulse width low is the minimum time clock pulse should be left in low state. At a given clock

rate, these specs define acceptable clock duty cycles.

offset error

The difference between the analog input voltage at which the analog-to-digital converter output changes from

negative full scale, to one LSB above negative full scale, and the ideal voltage at which this transition should

occur.

gain error

The maximum error in LSBs between a digitized ideal full scale low frequency offset corrected triangle wave

analog input, from the ideal digitized full scale triangle wave, divided by the full scale range, in this case 1024.

harmonic distortion

The ratio of the power of the fundamental to a given harmonic component reported in dBc.

integral nonlinearity

The deviation of the transfer function from an end-point adjusted reference line measured in fractions of 1 LSB.

Also the integral of the DNL curve.

output delay

The delay between the 50% point of the falling edge of the clock and signal and the time when all output data

bits are within valid logic levels (not including pipeline delay).

signal-to-noise-and distortion (SINAD)

When tested with a single tone, the ratio of the signal power to the sum of the power of all other spectral

components, excluding dc, referenced to full scale.

signal-to-noise ratio (SNR)

When tested with a single tone, the ratio of the signal power to the sum of the power of all other power spectral

components, excluding dc and the first 9 harmonics, referenced to full scale.

effective number of bits (ENOB)

For a sine wave, SINAD can be expressed in terms of the effective number of bits, using the following formula,

ENOB

+

(SINAD

* 1.76)

6.02

spurious-free dynamic range (SFDR)

The ratio of the signal power to the power of the worst spur, excluding dc. The worst spurious component may

or may not be a harmonic. The ratio is reported in dBc (that is, degrades as signal levels are lowered).