Tektronix TDS5032, Руководство пользователя

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Operating Basics
There are three categories of measurements: Low Speed, Full Speed, and High
Speed measurements. The measurements for Low, Full and High Speed signals
are Signal Quality Checks, Inrush Current Check, and Droop Test. The additional
measurements for High Speed tests are Receiver Sensitivity, Monotonic
Property, and Chirp Test, Packet Parameter, Suspend, Resume, Reset from
Suspend, and Reset from High Speed.
You need to select the measurements for a particular signal speed of the unit
under test. After selecting the tests, you must configure the application based on
Signal Source, Tier, Test Point, and Signal Direction.
You can test the units for the following:
Devices for Upstream Signal Quality Check
Hubs and Hosts for Downstream Signal Quality Check
Ports of a Hub for Droop Test
Devices for Inrush Current
Signal Quality Check
The application performs Signal Quality tests that include the following tests:
Table 6. Signal Quality checks
Area Option Description
Signal Quality Check Eye Diagram Checks whether the USB signal is aligned with its corresponding
eye diagram
Signal Quality Check Signal Rate Measures the inverse of the average bit-time that gives the
transmission rate of the USB signal
Signal Quality Check Paired JK Jitter Measures the jitter time for paired (JK next to KJ) differential
data transition
Signal Quality Check Paired KJ Jitter Measures the jitter time for paired (KJ next to JK) differential
data transition
Signal Quality Check Consecutive Jitter Measures the jitter at every consecutive data bit calculated
using the signal rate
Signal Quality Check EOP Width Measures the width of the end-of-packet of a USB signal
Signal Quality Check Cross-Over voltage Measures the voltage at which the D+ voltage crosses the D–
voltage
Signal Quality Check Rising Edge Rate
Measures the Rising Edge/Slew rate in V/
μ
s and is calculated
using the Rise time as
Rising Edge Rate = Amplitude / Rise Time
Where Amplitude is the peak-to-peak amplitude for the
corresponding signaling rate and the Rise time is calculated
based on the high level of the inner vertical eye height reference
levels
Signal Quality Check Falling Edge Rate
Measures the Falling Edge/Slew rate in V/
μ
s is calculated using
the Fall time as Falling Edge Rate = Amplitude / Fall Time
TDSUSB2 Universal Serial Bus Measurement Package 29