Readout Chip

Each silicon sensor pixel segment is electrically connected via an indium bump to a ROC pixel unit cell (PUC). The PUCs are arranged in 26 x 80 double columns which are controlled by the double column periphery. The double columns, the double 

The double column periphery verifies the trigger by comparing the time stamp with a counter running behind the bunch crossing counter by the trigger delay. In case of agreement the column is set into readout mode and the data acquisition is stopped, otherwise the data are discarded. When the readout token arrives at the double column periphery the validated data are sent to the chip periphery and the double column is reset. The ROCs are read out serially via a 40 MHz analog link. A picture of a BPIX readout chip is shown in Fig. 7.4. 

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Fig. 7.4 Picture of the BPIX readout chip highlighting the three main building blocks double column, double column periphery and chip periphery [6]...

H.C. KastU et al., Design and performance of the CMS pixel detector readout chip. Nucl. Instrum. Meth. A 565, 188 (2006)... 

Fig. 8.21 Number of hits associated to a track detected in each ROC for the first (left), second (middle) and third (right) barrel layers [13]. Bins in white correspond to readout chips excluded from data taking...

The readout chip will be a VLSI circuit consisting of a front-end amplifier, followed by a comparator, analog or digital storage, and a readout section. To minimize material and connections, the readout circuitry should be accomodated on a single IC. 

Fig. 12.5 Artist impression of the lab-on-a-chip structure for spectrophotometric analysis of biological fluids. (A) Microfluidic channels (B) Optical filters (C) Detection and readout chip (D) General scheme of the lab-on-a-chip structure.

No major investment is expected in the near future on Si P and Si Ga BIB detectors, as the advantages to be gained are not commensurate with the amount of technology development needed. In Ge Ga BIB detectors, demonstration of back-iUuminated arrays is the next step. Readout chips operating reliably with such arrays need to be developed and optimized. 

Eig. 18. Microbolometer (a) array portion showing pixels on a 50-pm pitch. Each pixel is coimected to a readout amplifier in the supporting siUcon IC chip, (b) Detector having a 35 x 40 pm active area. The serpentine arms give excellent thermal isolation and the low mass results in a 10-ms response time, ideal... 

Kohler J.M., Csaki A., Reichert J., Moller R., Straube W., Fritzsche W., Selective labeling of oligonucleotide monolayers by metallic nanobeads for fast optical readout of DNA-chips, Sens Act B 2001 76 166-172. 

Readout speed for a typical CCD camera is somewhere between 100 kpixel s 1 and 5 Mpixel s-1. Cameras with up to 4 Mpixel chips have been built. How-... 

This class of CCD has a higher quantum yield than a front-illuminated similar CCD. The origin of this improvement is as follows. The silicon substrate for the chip is etched down, on the face opposite the electrodes, to reach a thin layer (—15 pm), and the light illuminates the array from the back, opposite from the usual way (Fig. 4). It was noted in Sec. 5 that electrode gates that are used for the readout process overlap the pixel surface. Since these electrodes have a given thickness and are laid on the front face, photoelectrons have to travel across a... 

The first monolithic devices have been presented at the same time by a group at NIST and a group at the Physical Electronics Laboratory (PEL) of ETH Zurich [77-81]. The NIST chip hosts an array of microhotplates integrated with transistor switches and a readout amplifier for the sensitive layer. The device presented by PEL includes an analog temperature controller and a logarithmic converter for reading out the sensor values. This was the first monolithic realization of an embedded system architecture with integrated microhotplate. 

The chip is a standalone microsensor system that does not need any external measurement equipment for sensor control and readout. The sensor system chip has been connected to a computer via an f C-to-USB converter box, i.e., in this box is a microcontroller that translates the I C format coming from the chip into USB format for the computer or laptop. The power supply of the chip is also provided by the USB connection. The sensor system can be read out directly by a microcontroller and is, therefore, well suited for handheld devices or distributed sensor networks. 

We have demonstrated the feasibility of miniaturized MS assays by converting the cathepsin B assay described in Section 5.2.2 to a chip format, using the same substrate and products for the MS-based readout [27]. The assay set-up is identical to the format described in Fig. 5.1. The advantages of chips as micro reactors over fused silica capillaries are in their compactness, strength, greater degrees of freedom in design and material, and the presence of hair-pin curves to increase the diffusion rate. 

In a more modified approach, differential display proteomics can also be done with no separation of proteins. This is called the protein chip approach. In this method, a variety of bait proteins such as antibodies, peptides, or protein fragments may be immobilized in an array format on specially treated surfaces. The surface is then probed with the samples of interest. Proteins that bind to the relevant target can then be analyzed by direct MALDI readout of the bound material (Nelson, 1997 Davies et ah, 1999). Lor example, well-characterized antibodies can be used as bait. Protein samples from two different cell states are then labeled by different fluorophores, mixed together, and used as probe. In such a case, the fluorescent color acts as an indicator for any change in the abundance of the protein that remains bound to the chip (Lueking et ah, 1999). A number of technical problems would still need to be overcome before applying this technique for large-scale analysis of proteins. 

Another class of readout measures RNA expression levels, with the three most common methods being chip-based hybridization/fluorescence techniques, realtime polymerase chain reaction (RT-PCR) and quantitative nuclease protection assays (QNPA) [48, 49]. Chip-based methods are widely used for whole-genome scans (discussed in more detail below), but have a disadvantage that they are relatively expensive and so are not really high throughput. The quantitative reproducibility and dynamic range of these chip-based methods are also lower than for the other RNA readout techniques. RT-PCR is a more quantitative technique for measuring transcript levels, and is typically run for up to 40 transcripts at a time. QNPA is another... 

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