Readout Electronics: SIDECAR ASIC Hardware

SIDECAR ASIC 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 FEATURES 36 Analog Inputs 20 Digital I/O Clocks 20 Output Biases 36 16 bit ADCs 36 12 bit ADCs Taken from Loose et al. SPIE 2002 Taken from Loose et al. SPIE 2007

SIDECAR ASIC and H4RG HXRG ASIC JADE Computer 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 V going to detector SIMPLE INTERFACE HXRG Hirose Connector ASIC JADE SIDECAR ASIC attached to an H4RG and connected to DELL Laptop with a USB cable Have tested ASIC over 125 foot fiber/USB cable Computer USB Cable

External Electronics: Data from ASIC CONFIG AND SCIENCE DATA TO/FROM SIDECAR = Spartan 3- FPGA Xilinx Firmware written by Teledyne JADE CARD No Unix libraries or source code available for USB microcontroller! Only precompiled .dll files containing classes. EZ-USB FX2LP(TM) USB Microcontroller Quick USB DLL written by Bitwise = MICROSOFT COM FUNCTIONS HalWrapper.dll written in C# and .NET COMPUTER IDE Written by Teledyne IDL Code or Other interface

Setup used at ESO - Cryogenic ASIC sits inside dewar Figure taken from Dorn et al. Evaluation of the Teledyne SIDECAR ASIC…’, SPIE 2006 - Cryogenic ASIC sits inside dewar Standard LGA socket packaging provided by Teledyne 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

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 Simplified Portion of Routing Mux Detector Video Output Channel 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