  The design and performance of a fully-synchronous multi-GHz analog transient
waveform recorder I.C. ("SST") with fast and flexible trigger capabilities is
presented. The SST's objective is to provide multi-GHz sample rates with
intrinsically-stable timing, Nyquist-rate sampling and high trigger bandwidth,
wide dynamic range and simple operation. Containing 4 channels of 256 samples
per channel, the SST is fabricated in an inexpensive 0.25 micrometer CMOS
process and uses a high-performance package that is 8 mm on a side. It has a
1.9V input range on a 2.5V supply, exceeds 12 bits of dynamic range, and uses
~128 mW while operating at 2 G-samples/s and full trigger rates. With a
standard 50 Ohm input source, the SST exceeds ~1.5 GHz -3 dB bandwidth. The
SST's internal sample clocks are generated synchronously via a shift register
driven by an external LVDS oscillator running at half the sample rate (e.g., a
1 GHz oscillator yields 2 G-samples/s). Because of its purely-digital
synchronous nature, the SST has ps-level timing uniformity that is independent
of sample frequencies spanning over 6 orders of magnitude: from under 2 kHz to
over 2 GHz. Only three active control lines are necessary for operation: Reset,
Start/Stop and Read-Clock. When operating as common-stop device, the time of
the stop, modulo 256 relative to the start, is read out along with the sampled
signal values. Each of the four channels integrates dual-threshold trigger
circuitry with windowed coincidence features. Channels can discriminate signals
with ~1mV RMS resolution at >600 MHz bandwidth.
