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11/12/98

SPT9110

TIMING SPECIFICATION DEFINITIONS

ACQUISITION TIME

This is the time it takes the SPT9110 to acquire the analog

signal at the internal hold capacitor when it makes a transition

from hold mode to track mode. (See figure 1.) The acquisition

time is measured from the 50% input clock transition point to

the point when the signal is within a specified error band at the

internal hold capacitor (ahead of the output amplifier). It does

not include the delay and settling time of the output amplifier.

Because the signal is internally acquired and settled at the

hold capacitor before the output voltage has settled, the

sampler can be put in hold mode before the output has settled.

TRACK-TO-HOLD SETTLING TIME

The time required for the output to settle to within 4 mV of its

final value.

APERTURE DELAY

The aperture delay time is the interval between the leading

edge transition of the clock input and the instant when the

input signal was equal to the held value. It is the difference

in time between the digital hold switch delay and the analog

signal propagation time.

Figure 1 - Timing Diagram

Acquisition

Time

Aperture

Delay

Track-to-Hold

Settling

Hold

Track

Hold

CLK

NCLK

Output

Input

Observed at

Hold Capacitor

Observed at

Amplifier Output