{"id":935,"date":"2012-02-28T09:07:45","date_gmt":"2012-02-28T09:07:45","guid":{"rendered":"http:\/\/harvestimaging.com\/blog\/?p=935"},"modified":"2012-02-28T09:07:45","modified_gmt":"2012-02-28T09:07:45","slug":"report-isscc-2012-4","status":"publish","type":"post","link":"https:\/\/harvestimaging.com\/blog\/?p=935","title":{"rendered":"Report ISSCC 2012 (4)"},"content":{"rendered":"

<\/span><\/p>\n

Another nice pair of papers came from NHK and Samsung.\u00a0 <\/span>Especially their ADC attracted my attention : both papers made use of what I call myself a tandem-ADC.\u00a0 <\/span>This is an ADC that is build around two different architectures or two different working principles.\u00a0 <\/span>Last year\u2019s ISSCC had already such a device in a Sony sensor, in which the column ADC was split into two parts : one with counter and one without counter if I remember well.<\/span><\/span><\/p>\n

This time, NHK presented a very similar paper as the one presented at the International Image Sensor Workshop.\u00a0 <\/span>It is a 33 Mpixel UHDTV sensor with pixels of 2.8 um x 2.8 um, that is capable of operating at 120 fr\/s.\u00a0 <\/span>The ADC used was split into two parts, both are cyclic ADCs, delivering in total 12 bits.\u00a0 <\/span>The first 4 upper most bits are converted in a first cyclic ADC (based on 3 cycles), the last 8 lower most bits are converted in a second cyclic ADC (based on 8 cycles).\u00a0 <\/span>These two cyclic ADCs operate in a pipelined organization, in this way extra speed can be gained.<\/span><\/span><\/p>\n

The second presentation, Samsung\u2019s, discussed a 24 Mpixel APS-C size imager with 3.9 um x 3.9 um pixel size.\u00a0 <\/span>The on-chip ADC has a resolution of 14 bits in a full range of 1.7 V.\u00a0 <\/span>The circuit realizing the first 2 \u2026 6 bits, in combination with the CDS, is based on a delta-sigma converter.\u00a0 <\/span>The remaining 8 bits are converted in a cyclic ADC.\u00a0 <\/span>But actually the beauty of this construction is the fact that part of the delta-sigma and the cyclic ADC use the same building blocks.\u00a0 <\/span>And because the two parts work in series, several building blocks of the delta-sigma are used as well in cyclic ADC.\u00a0 <\/span>In this way the circuitry needed to realize the complete ADC remains relative small.\u00a0 <\/span>Cleaver idea !<\/span><\/span><\/p>\n

Talking about ADCs : Delft University of Technology presented a paper on a column-level ADC capable of doing multiple sampling without any increase of hardware.\u00a0 <\/span>The ADC is based on an up-counter with BWI (Bit-Wise-Inversion) to allow digital CDS.\u00a0 <\/span>In case multiple sampling is applied, the counters simply continue the counting for several consecutive samples.\u00a0 <\/span>Without any special pixel design, the multiple sampling (in combination with an extra column amplifier) resulted in a noise level of only 0.7 electrons.\u00a0 <\/span>The low conversion gain of the pixel (< 50 uV\/e-) clearly indicated further room for improvement.\u00a0 <\/span>Pixel noise levels of 0.28 electrons fabricated in \u201cstandard\u201d CIS processes are needed for single-electron\/photon detection.\u00a0 <\/span>This performance level is coming closer !<\/span><\/span><\/p>\n

More to come ? Maybe !<\/span><\/span><\/p>\n

Albert, 28-02-2012.<\/span><\/span><\/p>\n

\u00a0<\/span><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Another nice pair of papers came from NHK and Samsung.\u00a0 Especially their ADC attracted my attention : both papers made use of what I call myself a tandem-ADC.\u00a0 This is an ADC that is build around two different architectures or two different working principles.\u00a0 Last year\u2019s ISSCC had already such a device in a Sony […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-935","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/harvestimaging.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/935","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/harvestimaging.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/harvestimaging.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/harvestimaging.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/harvestimaging.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=935"}],"version-history":[{"count":1,"href":"https:\/\/harvestimaging.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/935\/revisions"}],"predecessor-version":[{"id":936,"href":"https:\/\/harvestimaging.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/935\/revisions\/936"}],"wp:attachment":[{"href":"https:\/\/harvestimaging.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=935"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/harvestimaging.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=935"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/harvestimaging.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=935"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}