Production I.Yield. II.Acceptance criteria. III.Test. PS & SPD LHCb Calo PRR – March 2004 – CERN

I. Yield. According to these results yield is about 85 %. No defect48 (40 in EDQUAD TQFP and 8 in JLCC) Supply short2 (EDQUAD TQFP) Digital interface error4 (2 EDQUAD TQFP and 2 JLCC) 1 subchannel is dead2 (EDQUAD TQFP)

II. Acceptance criteria (I). Possible scenario (using PMT load resistors of 470  ): –Signal 0 – 25 ns about 76 % and tail 25 – 50 ns about 22 % –MIP signal 0 – 25 ns between 83 and 21 mV for PMT uniformity factor of 4 (gain is 1.1 mV/fC). –Noise 2 mV r.m.s. –SNR for MIP signal is between 40 and 10. –Resolution is given by the LSB of the internal DAC, LSB=3.2 mV seems to be enough to cover the offsets of about the 95% of the chips. –Resolution between 4 % and 16 %. SNR can be increased if needed with larger PMT load resistors. It is possible to compensate the PMT gain non-uniformities and the ASIC offsets tuning the input resistors. DAC: Offset = 0 LSB = 4 Offset: µ = -70  = 55 µ-2.5  = LSB= -200 µ+2.5  = LSB= MIP 83 max. 143 Units are in mV

II. Acceptance criteria (II). Defects are found in about 15% of the chips. No special rejection criteria on offset is needed. No rejection criteria on linearity or pile-up correction seems to be needed since all the chips that have been tested are within requirements. A yield >80% is assumed To equip 100 boards, 800 chips are needed. To keep 20% of spare chips, a production of 1250 units is required

III. Test. The following points should be included in the test of the complete production: –Offset –Gain –Pile-up correction –Digital interface A new VHDL code is under development to accelerate the test (it will include threshold scan algotiyhms).