81250 Datasheet, PDF (38/64 Pages) Keysight Technologies – Agilent ParBERT 81250 Parallel Bit Error Ratio Tester

Agilent E4861B ParBERT 3.35 Gb/s Data Module
Agilent E4862B ParBERT 3.35 Gb/s Generator Front-End
Agilent E4863B ParBERT 3.35 Gb/s Analyzer Front-End
Technical Specifications
General
A ParBERT 3.35 Gb/s module
can house up to two front-ends,
either two generators or analyzers
or any mix. ParBERT 3.35 Gb/s
modules work with the E4808A
or E4890A clock modules. The
key specifications of ParBERT
3.35 Gb/s modules are:
• 21 MHz … 3.350 GHz
clock/data rate
• 16 Mbit memory depth at
each channel
• HW-based PRBS generation
up to the polynomial of
2³¹ -1
• Analyzer can synchronize on
a 48 bit detect word
(memory-based data)
• Analyzer can synchronize on
a pure PRBS pattern without
detect word
Timing capabilities
The frequency range of the
modules is 21 MHz … 3.350 GHz.
The ParBERT 3.35 Gb/s front-ends
use a multiplying PLL that multi-
plies system master clock by 4 or
8. Through the clock module, an
external clock source can be
used. This external clock must
run continuously. If the clock
signal is interrupted, the multi-
plying PLLs typically needs
100 milliseconds to lock onto
the clock again.
Figure 23. E4861B and E4862B with waveform of E4861B generator
Table 43. E4861B data generator timing specification (@ 50% of amplitude, 50 Ω to GND)
Frequency range
20.834 MHz to 3.350 GHz
Delay = start delay + fine delay Can be specified as leading edge delay in
fraction of bits in each channel
Start delay range
0 to 200 ns (not limited by period)
Fine delay range
±1 period (can be changed without stopping)
Delay resolution
1 ps
Accuracy data mode
±25 ps ±50 ppm relative to the zero-delay
and temperature change within ±10 °C
after autocalibration
Clock mode
±50 ps ±50 ppm relative to the zero-delay
Skew between modules of same 50 ps typ. after deskewing at customer
type (data mode)
levels and unchanged system frequency
The variable delay is available in data mode and pulse mode. In clock mode the timing is fixed.
Sequencing
The sequencer receives instruc-
tions from the clock module. The
channel sequencer can generate a
sequence with up to 60 segments.
An analyzer channel can gener-
ate feedback signals which are
combined in the clock module for
a common response of all parallel
channels. With a single receiver
channel the channel sequencer
itself handles the feedback signals.
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