Tektronix TDS2012C Service Manual

Specifications
Table 3: Triggering system (cont.)
Characteristic Description
This is the minimum peak–to–peak video signal required for stable Video-Type triggering.
Source
Typical sens itivity
Input Channels 2 divisions of composite video
Ext
400 mV of composite video
Video Trigger
Sensitivity, typical
Ext/5 2 V of composite video
Pulse-Width Trigger
Pulse-Width
Trigger Modes
< (Less than), > (Greater than), = (Equal), ≠ (Not equal)
Pulse Width
Trigger Edge
Falling edge for positive polarity pulse . Rising edge for negative polarity pulse.
Pulse Width Range 33 ns ≤ width ≤ 10 seconds
Pulse Width
Resolution
16.5 ns or 1 part per thousand, whichever is larger
t > 330 ns: ±5% < guardband < ±(5.1% + 16.5 ns)
t ≤ 330 ns: guardband = ±16.5 ns.
Equal Guardband
All pulses, even from the m ost stable sources, have some amount of jitte r. To avoid disqualifying pulses
that are intended to qualify but are not absolutely correct values, we provide an arbitrary guardband. Any
measured pulse width within the guardband will qualify. If you are looking for pulse width differences that
are smaller than the guardband width, offsetting the center should allow discriminating differences down
to the guardband accuracy.
330 ns < 1: ±5% ≤ guardband < ±(5.1% + 16.5 ns)
165 ns < 1 < 330 ns: guardband = -16.5 ns/+33 ns
t ≤ 165 ns: guardband = ±16.5 ns
Not Equal
Guardband
All pulses, even from the m ost stable sources, have some amount of jitte r. To avoid disqualifying pulses
that are intended to qualify but are not absolutely correct values, we provide an arbitrary guardband. Any
measured pulse width outside the guardband will qualify. If you are looking for pulse width differences
that are smaller than the guardband width, offsetting the center should allow discriminating differences
down to the guardband accuracy. Not equal has slightly better ability to deal with small pulse widths
than equal. The accuracy is not better.
Equal: The oscilloscope triggers when the trailing edge of the pulse crosses the trigger level.
Not E qual: If the pulse is narrower than the specified width, the trigger point is the trailing edge. Otherwise,
the oscilloscope triggers when a pulse continues longer than the time specified as the Pulse Width.
Less than: The trigger point is the trailing edge.
Pulse-Width
Trigger Point
Greater than (also called the time out trigger): The oscilloscope triggers when a pulse continues longer
than the time specified as the Pulse Width.
Trigger Frequency Counter
Trigger Frequency
Counter
This provides a highly accurate means of identifying the frequency of trigger signals. Since averaging
takes place over a longer time span, the number of stable digits is improved over the automatic
measurement of the same type.
12 TDS2000C and TDS1000C-EDU Series Oscilloscope Service Manual

Tektronix TDS2012C Specifications

General

Brand	Tektronix
Model	TDS2012C
Category	Oscilloscope
Language	English