  The design and performance of a multi-G-sample/s fully-synchronous analog
transient waveform recorder I.C. ("SST") with fast and flexible trigger
capabilities is presented. Containing 4 channels of 256 samples per channel and
fabricated in a 0.25 {\mu}m CMOS process, it has a 1.9V input range on a 2.5V
supply, achieves 12 bits of dynamic range, and uses ~160 mW while operating at
2 G-samples/s and full trigger speeds. With a standard 50 Ohm input source, the
SST's analog input bandwidth is ~1.3 GHz within about +/-0.5 dB and reaches a
-3 dB bandwidth of 1.5 GHz. The SST's internal sample clocks are generated
synchronously via a shift register driven by an external LVDS oscillator,
interleaved to double its speed (e.g., a 1 GHz clock yields 2 G-samples/s). It
can operate over 6 orders of magnitude in sample rates (2 kHz to 2 GHz). Only
three active control lines are necessary for operation: Reset, Start/Stop and
Read-Clock. Each of the four channels integrates dual-threshold discrimination
of signals with ~1 mV RMS resolution at >600 MHz bandwidth. Comparator results
are directly available for simple threshold monitoring and rate control. The
High and Low discrimination can also be AND'd over an adjustable window of time
in order to exclusively trigger on bipolar impulsive signals. Trigger outputs
can be CMOS or low-voltage differential signals, e.g. 1.2V CMOS or positive-ECL
(0-0.8V) for low noise. After calibration, the imprecision of timing
differences between channels falls in a range of 1.12-2.37 ps sigma at 2
G-samples/s.
