SURF ‘n TURF Gary S. Varner University of Hawai, i, Manoa ANITA Collaboration UC Irvine April 7 th, 2005

Gary S. Varner, ANITA Collab UC Irvine, April Talks Overview: 2 parts Sampling Unit for RF (SURF) evolution –Digitization: STRAW, LABRADOR generations –SURFpro evaluation, SURFv1 –Mezzanine card/DDTs Important System Issues: –Power DC draw update RF levels –Timing analysis –Testing plans/issues (TURFpro integration)

Gary S. Varner, ANITA Collab UC Irvine, April Basic trigger/digitizer data stream Split signal: 1 path to trigger, 1 for digitizer Use multiple frequency bands for trigger Digitizer runs ONLY when triggered to save power

Gary S. Varner, ANITA Collab UC Irvine, April Specifications

Gary S. Varner, ANITA Collab UC Irvine, April RF Digitizer checklist Sampling Rate >= 3GSa/s 12-bit ADC performance Analog Bandwidth >= 1.2 GHz Dynamic Range >= 9 bits

Gary S. Varner, ANITA Collab UC Irvine, April LABRADOR sampling & linearity Excellent ADC linearity Sampling rates up to 4 GSa/s with voltage overdrive

Gary S. Varner, ANITA Collab UC Irvine, April dB sine wave LABRADOR bandwidth Bandwidth measured by two separate methods: RF sine wave (1050MHz max) and transient impulses

Gary S. Varner, ANITA Collab UC Irvine, April LAB1 dynamic range 1V range = 971 counts (~1 count/mV) Low: 0.4mV/count Mid: 1.5mV/count High: 4.5mV/count

Gary S. Varner, ANITA Collab UC Irvine, April LABRADOR2 – Jing Cao Trans-impedance  source follower –LABRADOR2 ~1mV “noise”, > 1V full scale (and linear + non-inverted) 10 bits should be feasible No changes to RF feed/timing or power Initial testing early ’05 – didn’t understand results

Gary S. Varner, ANITA Collab UC Irvine, April LABRADOR/2 floorplan 8x HS Analog out, 1x MUX out 8 chan. * 256 samples 128x Wilk ADCs Analog “Superbuffers” Straight Shot RF inputs Random access:

Gary S. Varner, ANITA Collab UC Irvine, April LAB2 Test bench LAB2 (indistinguishable from this resolution)

Gary S. Varner, ANITA Collab UC Irvine, April LAB2 DC Linearity 1.5 counts/mV Linear Residuals 1.6V dynamic range (DC transfer) Key: Transimpedance  Source Follower Allows operation without input offset

Gary S. Varner, ANITA Collab UC Irvine, April LAB2 Problem Decided for SURF v.1, LABRADOR only option LABRADOR LAB2 For reasonable settling time, need strong sense I; However, closed channels strongly active

Gary S. Varner, ANITA Collab UC Irvine, April LAB3 (?)  Faster Readout: –Why not put an ADC in every storage cell? Readout could be < 100us (40us convert and 50us data transfer) No analog sample transfer (biggest headache) –Give up analog waveform out 9 RF channels (1 dedicated timing) Greatly simplified control Implement 4 bucket “tail catcher” Modified termination scheme –Truly 50  –No resistive drop across array

Gary S. Varner, ANITA Collab UC Irvine, April Architecture Comparison inputinput

Gary S. Varner, ANITA Collab UC Irvine, April Chip comparison LABRADOR, LAB2 LAB3 65 analog/control lines 3-deep nested state machine 41 analog/control lines (better VDD/GND) Very simple state machine

Gary S. Varner, ANITA Collab UC Irvine, April Trigger checklist Good Band spacing Sufficient amplitude through TDD Net length balancing

Gary S. Varner, ANITA Collab UC Irvine, April RFCeval – 0 th order prototype Quick Reference: RFCeval == Radio Freq Comp evaluation board STRAW == Self-Triggered Recorder for Analog Waveforms LABRADOR == Large Analog Bandwidth Recorder And Digitizer with Ordered Readout

Gary S. Varner, ANITA Collab UC Irvine, April SURFpro Pro = Prototype

Gary S. Varner, ANITA Collab UC Irvine, April Diode Detector Test (DDT) Eval Trigger Studies Filter Banding Tunnel Diode DDT Board DDT2 Board Filter Banding Tunnel Diode

Gary S. Varner, ANITA Collab UC Irvine, April Filter Banding some balancing needed band tuning

Gary S. Varner, ANITA Collab UC Irvine, April Modified Bands

Gary S. Varner, ANITA Collab UC Irvine, April Diode detector Response Needs amplification! 2.3  ~= 3.9 P/

Gary S. Varner, ANITA Collab UC Irvine, April SURF v1 SURF High Occupancy RF Trigger (SHORT) board

Gary S. Varner, ANITA Collab UC Irvine, April SURF v1

Gary S. Varner, ANITA Collab UC Irvine, April SURF v2? Improvements (?) –Routing simplification: 5 CPLDs + 1 FPGA  1FPGA More space for LAB(3?) routing – net length balancing –Dedicated reference timing channel? –Remove dedicated comparators? (use FPGA LVDS receivers as comparators – less EMI and power) Triggering OK (?) [isolate changes to SHORT board?]

Gary S. Varner, ANITA Collab UC Irvine, April Online Documentation

Gary S. Varner, ANITA Collab UC Irvine, April Much progress since last met in autumn –Some RF components STILL on order Plans: –Defer to after the break – additional input SURF board cost ~ 10k$ per board –All RF components (4.8k$ in Tunnel Diodes alone) Part I Summary

Gary S. Varner, ANITA Collab UC Irvine, April Part 2: Important System Issues: –Power DC draw update RF levels –Timing analysis –Testing plans/issues (TURFpro integration)

Gary S. Varner, ANITA Collab UC Irvine, April SURFv1 DC Power -5Vmay go away

Gary S. Varner, ANITA Collab UC Irvine, April SURFv1 RF Power

Gary S. Varner, ANITA Collab UC Irvine, April Timing Path TURF bridges cPCI modules along backplane--sees local trigger pattern across antenna clusters Issues data hold, then digitize if trigger pattern is satisfied

Gary S. Varner, ANITA Collab UC Irvine, April Diode Detector Test (DDT) Eval Trigger Studies DDT Board 2 times of interest: 1.Absolute time w.r.t. PPS 2.Channel-to-channel timing

Gary S. Varner, ANITA Collab UC Irvine, April Trigger Timing Measurement 2ns/bin 1.2ns resolution (Spartan-3) Local Oscillator Stability: 5x Freq. Mult. Jitter ~ 1.34ns Not timing resolution!

Gary S. Varner, ANITA Collab UC Irvine, April Timing Fan-out Jitter LABRADOR time encoding –Interpolate HITBUS (hold/Halt): 330ps/SQRT(12) ~ 95ps LVDS/CPLD fan-out jitter – many 100ps TURF fan-out intrinsic timing –To be evaluated –Now have SURF TURF link running, can test Dedicated timing signal (?) –LAB3 provides this option

Gary S. Varner, ANITA Collab UC Irvine, April Trigger Studies

Gary S. Varner, ANITA Collab UC Irvine, April Studies/Documentation Owed SURF User’s Manual (programmer’s manual) TURFIO User’s Manual TURF Trigger Timing measurement results FPGA discriminator study (DDT) Student project: Trigger sensitivity to non- Gaussian noise and self-generated noise

Gary S. Varner, ANITA Collab UC Irvine, April Specifications - anon

Gary S. Varner, ANITA Collab UC Irvine, April Ready for TV test: –Has been useful integration exercise –Most parts TV rated – qualify the rest Plans: –Evaluation of SURFv1 performance –Start serious TURF studies (how many boards needed?) –TV test hardware enough for EM flight Design issues: –More LABs needed (Rev. 1 or 3); when? –SURFv2 ? –Freeze design when? Part II Summary

Gary S. Varner, ANITA Collab UC Irvine, April Back-up slides

Gary S. Varner, ANITA Collab UC Irvine, April Template

Gary S. Varner, ANITA Collab UC Irvine, April Aside: LABRADOR sampling speed High/Low CTRL: Extend to 4 GSa/s Improve odd/event Low freq operation

Gary S. Varner, ANITA Collab UC Irvine, April Askaryan Signature Significant signal power at large frequencies Strong linear polarization (near 100%)