ASD Development History

Here is a list of the test chips we have submitted to date along with some test results.  See our Slide Archive for more presentations which have been given on these chips.
Name  Received  Description 
ASD99A  due Mar 99  ASD Lite final prototype with improved input ESD protection.
ASD98B  Nov 98  ASD Lite prototype. 4 identical ASD channels. Fully differential. Tail-cancellation shaping, disc, LVDS outputs. Several new features to reduce crosstalk and increase stability.  Now being tested; preliminary results are as expected.
ESD98A  Apr 98  Dedicated ESD (electrostatic discharge) protection chip. 16 input with different combinations of ESD structures and pre-amps. 
ASD97C  Apr 98  Test to optimize preamp size (2 options), LVDS driver type (2 options) and baseline-resoration (with/without). 
ASD97B  Feb 98  Preamp, shaper, baseline-restoration.  3 identical channels with linear output. 
ASD97AP  Nov 97  Second 0.5um HP chip. Preamp, shaper, plus discriminator and LVDS output. 
ASD97A  Apr 97  First test in 0.5um HP process, 3.3V power supply. Includes preamp and new pole/zero tail cancellation shaper. Most features of this chip could not be tested due to a processing problem which resulted in the capacitors being omitted from the chip! 
ASD96B    First fully-differential preamp+main amp+discriminator (no shaping)  This chip included further refinements in the preamplifier, many test structures for ESD protection, and LVDS (Low-Voltage Differential Signalling) outputs. Tested extensively on-chamber. 
PR96A  summer 96  An integrated 4-channel ASD 
DS795  fall 95  Discriminator Test Chip 
PR695  summer 95  Preamp Test Chip 

Integrated Test Chip "PR96A"

The latest test chip demonstrates that a low-noise, high-gain amplifier can be integrated on the same chip as a fast timing discriminator. We have tested the amplifier noise performance, gain and timing performance, and found them to agree well with simulations. For details, see SLIDES and PAPER recently presented.

Preamp Test Chip

This chip was fabricated in Orbit 1.2u CMOS and consisted of four channels of charge-sensitive preamplifier, additional differential-amp stages, and pad drivers. The design was made carefully symmetrical and fully differential to minimize channel-to-channel offsets. With this chip we were able to confirm the preamp operation and low offset voltages. Unfortunately due to a layout error we were not able to measure the noise performance.

Discriminator Test Chip

We have fabricated and tested an Orbit 1.2 micron CMOS test chip with three different discriminator designs. This chip proved that high-performance timing discriminators can be integrated in standard CMOS. There are three designs, "small", "medium" and "large" (referring to the size of the input transistors). The medium and large designs have externally programmable hysteresis. The small design illustrates that the required performance can be achieved in a very compact layout. Back to Front-End Electronics
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