Charge Injector Documents

Board Specifications

• Maximum charge output 330 pC (at 25 ns)
• Should cover the high-dynamic range of the QIE: 3 fC to 330 pC. The QIE has a logarithmic response over 4 ranges. Each range is divided in subranges. See this plot for range 0.
• RMS noise < 2 fC.
• 12 signal and 12 reference outputs.
• 3U or 6U board dimensions.
• Mounted in front panel a Winchester 24-channel connector.
• Power and DAC connectors on the back side of the board.

Circuit schematics

• Schematics of cardA (incomplete compared with cardB) pdf. The card v10 has the following modifications no included in the schematics:
  • DAC input connector for 12 channels was removed.
  • The DAC input are now reduced to only 4 inputs. Each of these inputs goes into an OpAmp AD823 setup as a unity gain amplifier. The output of the OpAmp is distributed into three subcircuits.
  • The output, reference and signal, of each subcircuit goes to the Winchester connector.
  • Three channels also can output into MMCX connectors in addition to the Winchester output.
  • One of the 200k resistor of the reference output was changed to a 400k resistor.
  • One of the caps of the subcircuit was removed (not mounted).
  • The resistor right after the OpAmp output was changed from 500 ohm to 2k ohm resistor.

• Kicad files of PCB layout Final_PCB.zip

• Schematic from circuitlab.com to run a simple simulation pdf.
  • The output current is given by Vin*R3/(R1*R5).

• The basis of the circuit comes from the schematic of the old board that was used to calibrate the QIE8 GIF

PCB layout for board version cardB v10

• Bill of materials (BOM) doc
• Top plane photo jpg
• Back plane photo jpg

Fixes to be done to cardB v10

• Produce an accurate schematics.
• Fix the location of the drill holes for rack mount.
• Connect ground on Winchester connector to rest of the board.
• Fix the footprint of the Winchester connector (it is currently rotated 180 degrees and inverted).
• Add buffer caps to power lines of OpAmps.
• Move caps close to OpAmps and place them so we can avoid induced currents.
• Remove unnecessary vias.
• Keep in mind the changes on resistors (500 -> 2k, ref 200k -> 400k) and removed cap.
• Add a couple of ground connections for DAC.
• Improve labels. Label GND in power connector and DAC.
• Check JTAG mapping.
• Check the Winchester mapping of sig/ref channels.
• (to be checked) add a RC filter to reduce noise, or add an inductor to increase impedance.

DAC

• We use the Measuring Computing USB 3105.
• Some of the main specs are below, for more details see manual:
  • 16 Bit resolution
  • 16 analog output
  • Voltage output range: 0 to +/- 10 V
  • LSB for unipolar 0->+10 V is 0.000153 V
  • LSB for bipolar 0 -> +/-10V is 0.000305 V
  • 8 digital I/O
  • One 32 bit counter

Other files

• Winchester connector footprint pdf
• 5-m Winchester cable connection pdf
• HF QIE10 card schematics pdf
• HF QIE10 card gerber and other files link
• HF QIE10 output channel map for Winchester connector pdf
• Dimensions of boards for racks/crates pdf

-- FranciscoYumiceva - 2015-06-17