Readout Electronics: SIDECAR ASIC

Hardware

SIDECAR ASIC

Taken from Loose et al. SPIE 2002

• Two sets of Control Electronics used: ARC and SIDECAR ASIC• SIDECAR has great functionality; very powerful chip• Challenge is to write assembly code to achieve functionality

SIDECAR FEATURES36 Analog Inputs20 Digital I/O Clocks20 Output Biases36 16 bit ADCs36 12 bit ADCs

Taken from Loose et al. SPIE 2007

SIDECAR ASIC and H4RG

• SIDECAR ASIC set up at Rochester Imaging Detector Laboratory

• All Clocks and Biases probed during power-up and regular operation No Voltages above 3.3 Vgoing to detector

SIMPLE INTERFACE

SIDECAR ASIC attached to an H4RG and connected to DELL Laptop with a USB cable

Have tested ASIC over 125 foot fiber/USB cable

ASIC

HXRGHirose Connector

ComputerUSB Cable

JADE

External Electronics: Data from ASIC

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JADE CARD Spartan 3- FPGAXilinx Firmware written by Teledyne

EZ-USB FX2LP(TM) USB MicrocontrollerQuick USB DLL written by Bitwise

MICROSOFT COM FUNCTIONSHalWrapper.dll written in C# and .NET

COMPUTER

IDE Written by Teledyne IDL Code or Other interface

CONFIG AND SCIENCE DATATO/FROM SIDECAR

No Unix libraries or source code available for USB microcontroller!Only precompiled .dll files containing classes.

Setup used at ESO

- Cryogenic ASIC sits inside dewar- Standard LGA socket packaging provided by Teledyne

Figure taken from Dorn et al. Evaluation of the Teledyne SIDECAR ASIC…’, SPIE 2006

JADE Card sits outside of dewar; JADE not used by SNAP team

Readout Electronics: SIDECAR ASIC

Firmware

Note: Fine details, likely not necessary for Corner Raft Meeting

SIDECAR Video Inputs

• SIDECAR ASIC has capacitively coupled inputs

• Capacitive feedback used for gain

• Leakage currents cause voltage at node to rise– Very noticeable at room

temperature– Must reset capacitors

periodically to prevent large rise

– Problem: kTC noise

Amplification – S3 and S6 are open

Special sample and hold circuitry able to sample voltage on Cfb as reference

kTC Noise Removal

Reset PreAmps once per frame

Drift of voltage is apparent over the frame

Reset PreAmps once per row

Different voltage due to kTC noise appearing on caps is visible from row to row

Reset PreAmps once per row with kTC removal

Row to row noise is eliminated

Simplified Portion of Routing Mux

SIDECAR ADC Averaging

• Noise of ADCs is ~2 ADU • To beat it down, average input on multiple ADCs• Input Routing Mux allows you to sample one input on 1-8 channels

Detector Video OutputChannel 7

Channel 6

Channel 5

Channel 4

Channel 3

Channel 2

Channel 1

Channel 0

ADC Averaging Results

• Noise goes down as 1/ as expected• Only works if 4 or less outputs of HxRGs are used• Second generation of SIDECAR ASIC expected to have lower noise

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NChannels