SOI Detector

(1) Mateusz Baszczyk, Piotr Dorosz, Sebastian Głąb,Wojciech Kucewicz, Łukasz Mik, Maria Sapor

(2) Imran Ahmed, Tomasz Fiutowski, Marek Idzik, Jakub Moroń

(3) Piotr Kapusta

(1) Department of Electronics,(2) Department of Particle Interaction and Detection TechniquesAGH – University of Science and Technology,Al. Mickiewicza 30, 30-059 Krakow, Poland(3) Institute of Nuclear Physics Polish Academy of ScienceRadzikowskiego 152, 31-342 Krakow, Poland

Agenda

• Chip topology• Pixel circuit;• Band Gap voltage source;• Analogue to digital converter;• Digital library;• Summary;• Future work.

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Assumptions

• Detector has to work but it’s parameters are not so important.

• Pixels with CDS and rolling shutter readout scheme.

• Possibility to measure wafer temperature.

• Functional 10 bit ADC with parallel data output (LVDS).

• We will take part in July submission.

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Chip layout

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• Detector has 32 pix x 32 pix;• Two slightly different layouts of

pixel;• Two Band Gaps;• Two 10 bit SAR ADCs;• Differential voltage signal.

Chip

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Pixel

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Designed by Piotr Kapusta

Pixel layout (30 um x 30 um)

7Designed by Piotr Kapusta

Negative temperature coefficient

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Forward voltage of p-n junction VBE has negative TC.

T

qEVmV

T

V gTBEBE/4

2

3m

eVEg 12.1

q

kTVT

With VBE = 750 mV, T = 300 K:

K

mV

T

VBE 5.1

Temperature exponent of mobility:

Thermal voltage:

Bandgap energy of silicon:

Positive temperature coefficient

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It was recognized in 1964 that if two bipolar transistors operate at unequal current densities, then the difference between their base-emitter voltages is directly proportional to the absolute temperature.

K

mV

T

VT 087.0

mnVV TBE ln

Band Gap

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Band Gap (280 um x 425 um)

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Band Gap („cold” diode model)

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Band Gap („hot” diode model)

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ADC (theory)

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+

-

+

-

DA

CD

AC

DA

CD

AC

SA

RS

AR

SA

RS

AR

Shift registerShift registerShift registerShift register

Bn-1 Bn-2 B0Bn-1 Bn-2 B0

VDAVDA Vin

Vin

SAR register: 100 110 111 110

111110101100011010001000

111110101100011010001000

VINVIN

ADC

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Designed by Marek Idzik and Tomasz Fiutowski

ADC (100 um x 400 um)

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Designed by Marek Idzik and Tomasz Fiutowski

Sampling circuit with bootstrap

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Designed by Marek Idzik and Tomasz Fiutowski

Sampling circuit with bootstrap

18M. Dessouky, A. Kaiser, Input switch configuration suitable for rail-to-rail operation of switched opamp circuits;Elect. Lett., vol. 35, no. 1, pp. 8-10, Jan. 1999.

Sampling circuit with bootstrap

19M. Dessouky, A. Kaiser, Input switch configuration suitable for rail-to-rail operation of switched opamp circuits;Elect. Lett., vol. 35, no. 1, pp. 8-10, Jan. 1999.

Sampling circuit with bootstrap

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Designed by Marek Idzik and Tomasz Fiutowski

9 bit DAC (segmented)

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Designed by Marek Idzik and Tomasz Fiutowski

Dynamic comparator

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Designed by Marek Idzik and Tomasz Fiutowski

Dynamic comparator

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Designed by Marek Idzik and Tomasz Fiutowski

Delay based on thyristor

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Designed by Marek Idzik and Tomasz Fiutowski

Delay based on thyristor

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Designed by Marek Idzik and Tomasz Fiutowski

Digital library

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94 Cells (81 completed, 13 missing layout).

Adders, AND, AndOrInvert, Buffer, Buffer with Enable, Tristate Buffer, D Flip-Flops,D Latches, INV, JK Flip-Flops, Multiplexers, NAND, NOR, OR, T Flip-Flops, XNOR, XOR.

DigitalLib

• Two libraries: Gates and DigitalLib.Gates contains parameterized symbols and is used to draw schematics of DigitalLib.

• HDF_DYNAMIC and DF_DYNAMIC were drawn by Tomasz Fiutowski. These cells have different layout constraints.MESH is a template for layout drawing.

• These cells do not have layout: D Flip-Flops with Enable,all JK Flip-Flops, most of T Flip-Flops.

• All cells have passed simulation, DRC and LVS test. But I do not give any guarantee for correct operation of digital circuit – you must test it by yourself!!!

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Conclusions

• We have designed first SOI detector in Lapis technology. It is starting point for further improvements;

• Simulation results have shown correct operation of ADC and Band gap voltage source;

• Digital library containing low height cells was made;(not tested yet)

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Future work

• IC will be measured immediately after shipment.It is possible to use SeaBoard as acquisition system.

• We plan to use column ADC to increase readout speed. Due to large amount of digital data we will design serializer and phased locked loop.

• We would like to take part in January MPW run.

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Thank you for your attention

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