By: Uriel Barron Matan Schlanger Supervisor: Mony Orbach Final Review March 2015

 Large Neutrino detector at the South Pole  A collaboration of 11 universities worldwide  Detection of short, extremely weak RF pulses over an area of 100km 2

 High Bandwidth (~850 MHz), rare (once every few months) and short (~100 ns) pulses  Strong price sensitivity – At least 37 stations, high frequency samplers cost thousands of dollars per channel  Power consumption requirements (~2W)– limited power at the South Pole  Sample 4 channels with one board

 LABRADOR – basic digitizing board for the ARA test bed, only 1 GSPS  IRS (Ice Radio Sampler) – series of ASICs created for the DDA  Best so far – IRS2, which can sample in 4 GSPS, but has a long dead time

 Design and simulate a low-cost sampler for high frequency short pulses, with low power consumption  Design will include BOM, electronic schematics, layers design and Gerber files

 Dead time < 1ms  Build-in EEPROM and temperature sensor  Standby power consumption < 1W  Low cost (exact price isn’t specified)

 Using a DRS4 Domino Wave Circuit to quickly save analogously ~2000 sample per channel  Instead of continuous high-frequency sampling, using regular ADCs  All components are on-the-shelf and significantly cheaper than high-frequency samplers.

 Using the domino effect to save analog high- frequency signals, and later digitize them slowly  Contains 8 channels, each channel can save up to 1024 samples  Supports cascading of channels  Sample speed is up to 5 GSPS

We have a little distortion, but…

The input circuit works well, and consumes 7.5mW per channel, which yield 30mW total power consumption.

 Recommended in the DRS4’s datasheet, because the DRS4’s output can be connected directly to the AD9222 inputs  8 channels, can shut down each channels to reduce the power dissipation to virtually 0 with short waking-up time  12-bit, serial outputs

 3 Supply voltages: V – Clock and peripheral components V – DRS V – ADC We will use regulators to get 2.5V and 1.8V  Total power dissipation of 300mW when idle, about 720mW during sampling bursts

We don’t have such voltage rises, so we’re fine with our bypass capacitors

 Backward compatibility – QSE connectors location is fixed, SMA connectors on the other side  DRS4 and ADC – according to design flow  Clock – near the DRS4’s clock input  Peripheral components and regulators – wherever convenient

Filters Regulators Clock EEPROM Temperature Sensor

 Main goal – shield the vulnerable analog signals from any external noises or crosstalk with digital signals  We will use 8 layers, since there’s no strict limit over the cost, and we can get better performances  This makes much room for shielding using fully conductive layers (power and ground)

1. Top – 1.8V and some wires near components 2. Analog Data 3. Analog Ground 4. Mixed data – general use V – both analog and digital 6. Digital Ground 7. Digital Data 8. Bottom – mostly connectors

 Most important – isolating analog signals from any noise This means using mixed data for analog signals only when there is no other option  Another consideration – length of analog signals, differential pairs and clock-data pairs should be the same

Top, Analog, Mixed, Digital

 We managed to make an almost complete separation between analog and digital layers.  Therefore, we can change the layers order to get an even better isolation  No crosstalk between analog and digital signals  Differences in analog lines’ length is completely negligible

1. Top - 1.8V 2. Analog Data 3. Analog Ground V 5. Digital Data 2 – Former “mixed data” 6. Digital Ground 7. Digital Data 8. Bottom

 We used only reliable on-the-shelf products  900 MSPS to 5 GSPS sampling speed  Approximate power consumption of 300mW when idle, 720mW during sampling bursts  Strong shielding of analog signals  Approximate cost of 216$, instead of 8000$  Dead time: 66μs

 Better input circuit with op-amps  Reduce to 6 layers board  Use advanced readout modes to reduce dead time  Integrate 2 DRS4s  Adapt the DRS5