Choosing the right preamplifier/discriminator comparing advantages and drawbacks : NL-277-L (Nanometrics), ASD-8 (Cern) and MAD4 (INFN Italy) Our favorite: "The MAD"-Chip optimized for DC readout very fast, low crosstalk, LVDS output 1 Chip: 4 preamp/discriminator very cheap: ~$8/channel received 5 MAD chips + test board from INFN Italy for evaluation

The MAD-Chip Board En/Disabling channels over I2C bus (Philips PCF8577) MAD Chips Example shown here: 16 channel Frontend Board (INFN Italy) Input for test signal 16 chan output (LVDS->TDC) Threshold Setting Temperature Readout Front Side Front side of board Test points

The MAD-Chip Board Example shown here: 16 channel Frontend Board (INFN Italy) Back Side Input for test signal Differential wire signal inputs (as close to MAD chips as possible) Back side of board

Principle of a traditional delayline readout Example for a delayline readout with an interleave factor Fi=3 and N=4 Total number of TDC channel needed for delayline readout (2x Dual VDC chambers) #chan = 2*FI*Nplanes with FI=8 = 2*8*8 = 128 channels (=64/Octant) -> 256 channels (Top/Bottom RO) Qweak: FI=8, Tau=2ns or less, (depends on TDC resolution) N=18 (top/bottom RO) Max Deadtime: N*Tau ~36ns

8 TDC channels “Top readout” of 141 wires “Bottom readout” of 141 wires Principle of the Encoding Readout System (EROS) 8 x 5-Bit Bus for decoding the channel number (8*2^5 = 256 max) To Pattern Logic (40 channels) To Pattern Logic (40 channels) 282 wires per plane, Read out by 16 TDC channels and a 2*256 Pattern Unit. (VDC: Max 8 simultaneous wire hits per track) Channel Bit Pattern (2^5 =32) -> Delayline free readout (less dead time) Preamplifier/ Discriminator (MAD Board)

Wire Signal Readout using a flexible board Material: DuPont Pyralux Copper-Clad Laminate+Adhesive available in single, double, and mulilayer version can be photoetched like a regular PCB max format: 24"x36" (610x914) FR 9150: Kapton 127um, copper 35um, adhesive 25um (used for Mainz Drift Chambers) Need X Pyralux boards (18 per plane, 8 planes total) Up to now: All boards have the same layout. Might change with placing precision dowel pins on wire frame Pyralux board will contain holes for screws (keep out zone) Unclear: Do we need additional shielding like grounded copper strip between signal copper strip, and/or signal plane between grounded copper planes (sandwiched) Shielding might add unwanted input capacity According to MAD data sheet: input impedance ~ Glue area: 7” x 4.6” Length from Frame to MAD board is not fixed (assumed 2”) Input: 16 wires (gold plated tungsten, 25um diameter) Output: (SMD) connector, will be plugged on 16 channel MAD board Photoedged Copper lines Pyralux area with an adhesive Pyralux area without an adhesive

MAD Board Specification One Frontend Board (FEB) reads out 16 channels 4 MAD chips Enable/Disable of individual output channels (I2C) Input for test signal (offline test) temperature readout (sum of 4 MAD chip temperature sensors) Board Size: ~6” x ~2”, INFN needed 4 layers Max Width: 160mm given by wire spacing The connector for the incoming wire signal should be on board, minimizing the distance to the MAD chip inputs The board should be pluggable. The plug provides the low voltages. Slow Control (multiplexing) with I2C chips Local controll of a FEB: PCF8577 (32 I/O’s) 3-Bit Address Multiplexing of the PCF8577 done globally using a PCF8574 (8 I/O’s) Information about the MAD chip: and sub-links

16 channel output Connector (LVDS) 8 channel input connector 8 channel input connector I2C Channel Control (backside?) MAD Chip INFN Layout (154x44 mm) Qweak possible Layout Connection to Ground bar (+ Mounting Holes) Daisy Chain I2C Bus Vref, Vthres Input for test signal