DS1021

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DALLAS SEMICONDUCTOR TEST CIRCUIT Figure 4

TEST SETUP DESCRIPTION

Figure 4 illustrates the hardware configuration used for measuring the timing parameters of the DS1021.

The input waveform is produced by a precision pulse generator under software control. Time delays are

measured by a time interval counter (20 ps resolution) connected to the output. The DS1021 serial and

parallel ports are controlled by interfaces to a central computer. All measurements are fully automated

with each instrument controlled by the computer over an IEEE 488 bus.

TEST CONDITIONS

INPUT:

Ambient Temperature:

25°C ± 3°C

5.0V ± 0.1V

Input Pulse:

High = 3.0V ± 0.1V

Low = 0.0V ± 0.1V

Source Impedance:

50 ohms max.

Rise and Fall Time:

3.0 ns max.

(measured between 0.6V and 2.4V)

Pulse Width:

500 ns (DS1021–25)

2 µs (DS1021–50)

Period:

1 µs (DS1021–25)

4 µs (DS1021–50)

NOTE: Above conditions are for test only and do not restrict the operation of the device under other data

sheet conditions.

OUTPUT:

Output is loaded with a 74F04. Delay is measured between the 1.5V level of the rising edge of the input

signal and the 1.5V level of the corresponding edge of the output.

DS1021