IC227 Datasheet, PDF (3/22 Pages) IC-Haus GmbH – DUAL 11 GHz SAMPLING OSCILLOSCOPE

iC227
preliminary
DUAL 11 GHz SAMPLING OSCILLOSCOPE
BLOCK DIAGRAM AND THEORY OF OPERATION
Rev B1, Page 3/22
iC227 is a simple yet very fast and accurate oscillo-
scope, consisting of a micro-controller and high speed
ECL differential circuitry.
The micro-controller receives commands and re-
sponds via an isolated USB interface running in full
speed mode at 12 Mbit/s.
The sequential scope works by inserting incremental
delays between trigger and sample circuit.
A Sample is taken on both channels simultaneously
after delay line counting is completed.
It is important to note, that each ADC conversion re-
quires multiple trigger events, limiting the scope usage
to repetitive signals only.
Achieving highly accurate and repeatable time base is
done using proprietary self calibration and fine tuning
techniques.
ADC conversion can not start without a trigger event.
Once the trigger has been fired, a high-speed flip flop
is set and the programmable delay lines starts count-
ing time in 10 ps increments.
A fine tuning voltage adjusts final time delay with
one picoseconds resolution using DAC calibration data
from micro-controller flash memory.
The device time base is calibrated after assembly and
users have the option to run auto time base calibration.
Time base calibration takes long time, since time base
is scanned with 1 ps intervals and multiple cycles are
repeated, compared to time generated by the crystal
and stored in a flash calibration look up table.
There is no need for frequent time base calibration
since the ECL logic is stable over temperature.
Figure 1: Block Diagram