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1 ASET Colloquium on LAXPC Payload Electronics: Design challenges & philosophy, Subsystem Configurations and Developmental Overview : Part – 2 Presented.

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Presentation on theme: "1 ASET Colloquium on LAXPC Payload Electronics: Design challenges & philosophy, Subsystem Configurations and Developmental Overview : Part – 2 Presented."— Presentation transcript:

1 1 ASET Colloquium on LAXPC Payload Electronics: Design challenges & philosophy, Subsystem Configurations and Developmental Overview : Part – 2 Presented by Dhiraj K. Dedhia & Ravi Lakshman LAXPC – ASTROSAT PROJECT On behalf of LAXPC Team

2 2 LAXPC – ASTROSAT SATELLITE LAXPC UVIT SSM CZT SXT STAR SENSOR

3 3 LAXPC – CHARACTERISTICS  Area: 6,000 cm 2.  Mass: 390 kg.  Energy Resolution: 8-9% at keV.  Detection Efficiency: % upto 20 keV, ~50% upto 80 keV.  Time Resolution: 10 µs, dead time µs.  Front-end and Processing Electronics: Separate electronics for each detector.  Data Storage: Onboard Memory 570 MB per Orbit.  Life Time: 5-10 Years.

4 4 Event Processing Logic. Presented by Dhiraj K. Dedhia LAXPC – ELECTRONICS

5 5 LAXPC – DETECTOR FRAME Anode Wire: Gold coated Stainless Steel, 37 micron diameter: 60 (main)+ 46 (veto) Cathod Wire: BeCu, 50 micron diameter (~500)

6 6 LAXPC – EVENT PROCESSING LOGIC

7 7  Simultaneously Process 10 signals from CSPAs.  Generate event ID.  Generate 10 bit Pulse Height information.  Tag the Event arrival time with 10µs accuracy.  Generate pulses for colour-counts and quick look data.  Operational flexibility.  Self calibration feature.  Detector calibration option.  Minimum system dead time to handle high event rate. LAXPC – EVENT PROCESSING LOGIC

8 8  Any event outside 3 to 80 keV band should be rejected.  More than two simultaneous events should be rejected.  Any event accompanied by an ANTI event should be rejected.  Two simultaneous events should be accepted for counting, only if one of them is K-fluorescent event.  Two simultaneous events should be accepted for event mode.  Specific ANTI events should be accepted for detector calibration. LAXPC – EPL - SELECTION CRITERIA

9 9 LAXPC – EPL - BLOCK DIAGRAM

10 10 LAXPC – EPL - BLOCK DIAGRAM

11 11 LAXPC – EPL - BLOCK DIAGRAM

12 12 LAXPC – EPL - BLOCK DIAGRAM

13 13 LAXPC – EPL – FE DAUGHTER CARD

14 14 LAXPC – EPL – ADC DAUGHTER CARD

15 15 LAXPC – EPL – PRO DAUGHTER CARD

16 16  System dead time for genuine events is 25  S and 10  S for non- genuine events.  Capacity to process upto 40,000 Events / second.  All events are time tagged to an accuracy of 10  S.  Accepted event(s) digitized to 12bit Pulse Height information and classified with Anode ID.  Generates pulses for Broad Band Counting in various energy bands (colour-counts) and quick look data.  Facility to Mask each individual input by command.  The LLD, ULD, ANTI, K-band and Colour-count thresholds are command controllable.  Flexibility in Event selection criteria.  Provision for detector gain monitoring.  Provision for self-calibration. LAXPC – EPL - FEATURES

17 17 LAXPC – EPL - TIMING WAVEFORM Genuine Event time line.

18 18 LAXPC – EPL - TIMING WAVEFORM Non-Genuine Event time line.

19 19 LAXPC – EPL - TEST Screen capture for Non-Genuine Event time line.

20 20 LAXPC – EPL - TEST Screen capture for Genuine Event time line.

21 21 LAXPC – LAB MODEL OF TWO EPL

22 USE OF FPGA FOR BROAD BAND COUNTING & SATELLITE BUS INTERFACE Ravi V. Lakshman LAXPC – ASTROSAT PROJECT

23 23 3 Independent channels from EPL 2 Microcontrollers and 1 FPGA Microcontrollers –Event Tagging – Tag Events based on anode ID and time –Histogram Generation – Generate 10bit Histogram in selected energy bands FPGA – Broad Band Counting –Color Counts and Diagnostic Counts LAXPC – POST PROCESSING

24 24 Colour Counts: Provides information on the rate of occurrence of events with respect to the Layer on the Detector and the Energy Band the event represents Diagnostic Counts: This provides Quick Look data towards the nature of the events that are being analysed LAXPC – COUNTERS

25 25 LAXPC – LAYER IDENTIFICATION

26 26 LAXPC – COLOUR COUNTS

27 27 Diagnostic CounterDiagnostic Counter More Than Two Simulatneous Events (MTT)More Than Two Simulatneous Events (MTT) More Than One Simulatneous Events (MTO)More Than One Simulatneous Events (MTO) Integral Count Rate Of Analysed Events (CC)Integral Count Rate Of Analysed Events (CC) None Of Two Simlutaneous in K (NK)None Of Two Simlutaneous in K (NK) Double Event 1 : One K event + One Non K event (DEK - L1)Double Event 1 : One K event + One Non K event (DEK - L1) Double Event 2 : One K event + One Non K event (DEK - L2)Double Event 2 : One K event + One Non K event (DEK - L2) Double Event 3 : One K event + One Non K event (DEK - L3)Double Event 3 : One K event + One Non K event (DEK - L3) Two K events Simulatneously from any layerTwo K events Simulatneously from any layer Diagnostic CounterDiagnostic Counter More Than Two Simulatneous Events (MTT)More Than Two Simulatneous Events (MTT) More Than One Simulatneous Events (MTO)More Than One Simulatneous Events (MTO) Integral Count Rate Of Analysed Events (CC)Integral Count Rate Of Analysed Events (CC) None Of Two Simlutaneous in K (NK)None Of Two Simlutaneous in K (NK) Double Event 1 : One K event + One Non K event (DEK - L1)Double Event 1 : One K event + One Non K event (DEK - L1) Double Event 2 : One K event + One Non K event (DEK - L2)Double Event 2 : One K event + One Non K event (DEK - L2) Double Event 3 : One K event + One Non K event (DEK - L3)Double Event 3 : One K event + One Non K event (DEK - L3) Two K events Simulatneously from any layerTwo K events Simulatneously from any layer Counter DescriptionBits More than two simultaneous events (MTT)16 More than one simultaneous events (MTO)16 Integral count rate of analysed events (CC)16 None of two simultaneous events in K–Band (NK)16 Double events: One K event + one non K event (DEK – L1)8 Double events : One K event + one non K event (DEK – L2)8 Double events : One K event + one non K event (DEK – L3)8 Two K band events simultaneous in any of the layers8 D i a g n o s ti c C o u n t e r MoreThanTwoSimulatneousEvents(MTT)MoreThanTwoSimulatneousEvents(MTT) MoreThanOneSimulatneousEvents(MTO)MoreThanOneSimulatneousEvents(MTO) IntegralCountRateOfAnalysedEvents(CC)IntegralCountRateOfAnalysedEvents(CC) NoneOfTwoSimlutaneousinK (NK)NoneOfTwoSimlutaneousinK (NK) DoubleEvent1:OneK event+ OneNonK event(DEK -L1)DoubleEvent1:OneK event+ OneNonK event(DEK -L1) DoubleEvent2:OneK event+ OneNonK event(DEK -L2)DoubleEvent2:OneK event+ OneNonK event(DEK -L2) DoubleEvent3:OneK event+ OneNonK event(DEK -L3)DoubleEvent3:OneK event+ OneNonK event(DEK -L3) TwoK eventsSimulatneouslyfrom anylayerTwoK eventsSimulatneouslyfrom anylayer MoreThanTwoSimulatneousEvents(MTT)MoreThanTwoSimulatneousEvents(MTT) MoreThanOneSimulatneousEvents(MTO)MoreThanOneSimulatneousEvents(MTO) IntegralCountRateOfAnalysedEvents(CC)IntegralCountRateOfAnalysedEvents(CC) NoneOfTwoSimlutaneousinK (NK)NoneOfTwoSimlutaneousinK (NK) DoubleEvent1:OneK event+ OneNonK event(DEK -L1)DoubleEvent1:OneK event+ OneNonK event(DEK -L1) DoubleEvent2:OneK event+ OneNonK event(DEK -L2)DoubleEvent2:OneK event+ OneNonK event(DEK -L2) DoubleEvent3:OneK event+ OneNonK event(DEK -L3)DoubleEvent3:OneK event+ OneNonK event(DEK -L3) TwoK eventsSimulatneouslyfrom anylayerTwoK eventsSimulatneouslyfrom anylayer Diagnostic CounterDiagnostic Counter More Than Two Simulatneous Events (MTT)More Than Two Simulatneous Events (MTT) More Than One Simulatneous Events (MTO)More Than One Simulatneous Events (MTO) Integral Count Rate Of Analysed Events (CC)Integral Count Rate Of Analysed Events (CC) None Of Two Simlutaneous in K (NK)None Of Two Simlutaneous in K (NK) Double Event 1 : One K event + One Non K event (DEK - L1)Double Event 1 : One K event + One Non K event (DEK - L1) Double Event 2 : One K event + One Non K event (DEK - L2)Double Event 2 : One K event + One Non K event (DEK - L2) Double Event 3 : One K event + One Non K event (DEK - L3)Double Event 3 : One K event + One Non K event (DEK - L3) Two K events Simulatneously from any layerTwo K events Simulatneously from any layer Diagnostic CounterDiagnostic Counter More Than Two Simulatneous Events (MTT)More Than Two Simulatneous Events (MTT) More Than One Simulatneous Events (MTO)More Than One Simulatneous Events (MTO) Integral Count Rate Of Analysed Events (CC)Integral Count Rate Of Analysed Events (CC) None Of Two Simlutaneous in K (NK)None Of Two Simlutaneous in K (NK) Double Event 1 : One K event + One Non K event (DEK - L1)Double Event 1 : One K event + One Non K event (DEK - L1) Double Event 2 : One K event + One Non K event (DEK - L2)Double Event 2 : One K event + One Non K event (DEK - L2) Double Event 3 : One K event + One Non K event (DEK - L3)Double Event 3 : One K event + One Non K event (DEK - L3) Two K events Simulatneously from any layerTwo K events Simulatneously from any layer LAXPC – DIAGNOSTIC COUNTERS

28 28 Counters Required – 35 nos. (combination of 16 and 8 bit) Over-flow flag BIN time - 8ms to 1024ms Status Latch REAL TIME at start of BIN period Low Dead Time 8 bit bus to the SSR interface FPGA LAXPC – COUNTER REQUIREMENTS

29 29 74HC590 based discrete design made Number of IC’s > 60 Hence proposed to use an FPGA Actel RT54SX32-SU CQFP-208 And Actel ProAsic A500K050 CQFP-208 for Prototyping LAXPC – Discrete v/s FPGA

30 30 LAXPC – AIM

31 31 LAXPC – Design Flow

32 32 LAXPC – Programming the FPGA

33 33 Timing and Status Information (8 bytes) To Low Bit-rate Telemetry (LBT) Event Processing Electronics (EPL) System Time Base Generator (STBG) 35 Event Pulses BBC ELECTRONICS Bin Period F P G A MONO LATCHES 8 bit Data INT Clock SSR INTERFACE FPGA LAXPC – Block Diagram

34 34 00 Latch CounterLatch Mono Clear Clock Counter Bin OE BUS LAXPC – What must FPGA do ?

35 35 cellcount AND317 DFF16 DFFC16 OB33PH16 XOR215 AND27 GL333 INV1 PWR1 GND TOTAL93 NETLIST LAXPC – Implementation In FPGA

36 36 LAXPC – Simulation of BBC

37 37 LAXPC – SSR INTERFACE SIMULATION

38 38 LAXPC – SSR INTERFACE WAVEFORMS

39 39 LAXPC – Output Data

40 40 Event Processing Logic dead time = 25 μsec. Maximum Event Processing Rate = 40,000 Fast Counters mode eliminates the bottle neck of the dead time Works in parallel with Broad Band Counting and Histogram Mode. Number of photons decreases rapidly as the energy increases therefore 2-20 keV band only. Event Rate for the Top Layer – Anode 1 and Anode 2 4 energy bands with a fixed bin period of 160 microseconds Dead time = Recovery Time for CSPA = 15 μsec. LAXPC – Fast Counters

41 41 Comparators fed voltage proportional to indicated Energy. LAXPC – Fast Counter - Schematic

42 42 Comp 2-1 Comp 2-2 Comp 2-3 Comp 2-4 Comb. Logic 2-1 Comb. Logic 2-3 Comb. Logic 2-2 Comb. Logic 2-4 Comp 2-5 CSPA-A2 O/P 3keV 6keV 8keV 12keV 20keV A B C D Comparators fed voltage proportional to indicated Energy. LAXPC – Fast Counter - Schematic

43 43 LAXPC – Fast Counter – Circuit.

44 44 Funnels Data from 3 independent post processing channels to the Base Band Data Handling system Inputs from DELI-1 and DELI-2 in packets of 2048 bytes. Inputs from BBC counter in Packets of 64 Bytes. LAXPC – BDH Interface

45 DELI μC2FIFO DELI - 2 DELI μC1FIFO DELI - 1 EPL μC Event Processing Logic Dual Port Ram DELI μC1FIFO DELI - 1 DELI μC1FIFO DELI - 1 Combinational Logic and Gates Broad Band Counters Detector and Front End Electronics FIFO for BBC SERIAL STREAM LVDS INTERFACE Base Band Data Handling System Command decoder Tele-Command S.S.R Y Tx

46 46 data clock slot LAXPC – SSR INTERFACE

47 47 THANKS Mahendra Shah Parag Shah Mandar Saraf Vasant Gujar Sameer Patel Sheetalkumar Jadhav Jayendrasinh Parmar Varsha Chavan Devidas Pawar Dhiraj K. Dedhia Ravi Lakshman LAXPC – ASTROSAT PROJECT


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