Readout ASIC Development VERITAS II Garching, 28 January 2014 Matteo Porro

Focal Plane ASICs x 256 Switcher ASICs  Steering of DEPFET Arrays (Row-select; Pixel reset)  Provided so far by Heidelberg University  Heidelberg would be a natural provider for the future Readout ASIC  So far partially or completely developed at MPE/HLL  MPE has the expertise in low-noise readout  The existing ASTEROID ASIC will be used for MIXS of BepiColombo  VERITAS ASIC is being developed for ATHENA Readout ASIC Switcher ASIC Example of DEPFET prototype focal plane arrangement 2

ASICFilterFilter architecturepnCCDDEPFET SF DEPFET CR Dynamic range CAMEXMCDSUnipolar, single-ended, two stages  low*, high** VELA 1 TrapezoidalUnipolar, single-ended, two stages  low ASTEROID 1 TrapezoidalUnipolar, single-ended, two stages  low VERITAS 1.0TrapezoidalUnipolar, single-ended, two stages  low, high VERITAS 2.0Trapezoidalbipolar, fully differential, single stage low, high 1 In collaboration with Politecnico di Milano, L. Bombelli and C. Fiorini XMM-Newton and FEL experiments pnCCD with CAMEX BepiColombo DEPFET array with ASTEROID *Synchrotron and FEL applications ** Spectroscopy, X-ray astronomy, fast optical astronomy. 3

DEPFET Readout ASICs 4 MAIN CHARACTERISTICS AND FEATURES  Row-wise readout (parallel readout of all the pixels in one sensor row)  Analog Multiplexing  Biasing of DEPFET arrays  Two possible input stages for:  Source Follower readout  AC coupling -> easy to operate  Long settling time  Drain Readout  bias current cancellation required  Very short settling times  Optimum analog shaping (trapezoidal Weighting function)  Window mode

ASTEROID for BepiColombo 5 55 Fe T=-60 °C Mn-Kα 0.9µs integration clear settling  Source Follower readout  Total readout time: 4.8µs (1+0.9x2+2)  Effective signal processing time 1.8  s  energy resolution 5.9 keV)  eV (singles)  128 eV (all events)  peak/background ratio 3.000:1 Asteroid

VERITAS II ASIC 6 Analog section (64 ch.) 4.6 mm 6.9 mm S&H and MUX SPI control & SRAM  AMS CMOS 0.35  m 3.3 V  Two readout modes: Source Follower Readout / Drain Readout  Targeted readout time per row with drain readout ~ 2.5  s  Fully differential architecture  64 readout channels  MUX 64:1 – design speed 32 MHz  Total power ~ mW  Can be used also with pnCCDs (The use of the ASIC by different groups is beneficial for fast development)  First version is available and is under test

 Results with SF are comparable with those obtained with ASTEROID  The non-optimal resolution is due to the used DEPFET  Investigation of the drain readout is ongoing  An optimized redesign is foreseen in one year  Bug fixing  Optimization of parameters for ATHENA requirements  Possible additional features Mn-Kα 55 Fe T=-60 °C Preliminary results and outlook 7

References 8  M. Porro et al. "VERITAS: A 128-channel ASIC for the readout of pnCCDs and DEPFET arrays for X-Ray imaging, spectroscopy and xfel applications", IEEE Transactions on Nuclear Science, vol. 60, no. 1, pp , 2013  P. Majewski et. al, "DEPFET macropixel detectors for MIXS: Integration and qualification of the flight detectors", IEEE Transactions on Nuclear Science, vol. 59, no. 5 PART 3, pp , 2012  A. Meuris et al. "Development and characterization of new 256 × 256 pixel DEPFET detectors for x-ray astronomy", IEEE Transaction on Nuclear Science, vol. 58, no. 3 PART 3, pp , 2011  M. Porro et al. "ASTEROID: A 64 channel ASIC for source follower readout of DEPFET arrays for X-ray astronomy", Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 617, no. 1-3, pp , 2010  M. Porro et al., "Spectroscopic performance of the DePMOS detector/amplifier device with respect to different filtering techniques and operating conditions", IEEE Transactions on Nuclear Science, vol. 53, no. 1, pp , 2006  E. Gatti, et al., “Optimum filters for detector charge measurement in presence of 1/f noise,” Nucl. Instrum. Methods A, vol. 287, pp. 513–520, 1990