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SVD2 System test status

SVD2 System test status. Problem 1 Around 4/15, we met current shortage problem. On VA parameter tuning To obtain shorter shaping time(Tp), we changed “mbias”. Mbias defined DAC range inside VA1TA Mbias = 0.9mA/hybrid, Tp= 1.2us ⇒2.0mA(Typ. on VA manual) , Tp= 700ns

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SVD2 System test status

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  1. SVD2 System test status • Problem 1 • Around 4/15, we met current shortage problem. • On VA parameter tuning • To obtain shorter shaping time(Tp), we changed “mbias”. • Mbias defined DAC range inside VA1TA • Mbias = 0.9mA/hybrid, Tp=1.2us ⇒2.0mA(Typ. on VA manual) , Tp=700ns • Finally, we found a current shortage occurred on MAMBO and PS. • Modified MAMBO and PS Cabling⇒Solved on 53 and 5/13

  2. Power supply system Power Supply×10 DOCK +/-7.5～9.5V +5V Analog+ (5A) VA1TA 3A REBOx3 +3V +1.5V 3A 1A -5V Analog- (10A) 2A -3V -2.0V 6A 2A +5V Digital+ (5A) 3A Solved! -5V Digital- (5A) 3A MAMBO

  3. Power supply +V 1.6times lager than expected value Power Supply DOCK +5V Analog+ (5A) VA1TA 3A REBOx3 +3V +1.5V 3A 1A -5V Analog- (10A) 2A -3V -2.0V 6A 2A Modification has been succeeded!! +5V Digital+ (5A) 3A -5V Digital- (5A) 3A MAMBO

  4. System test status(cont’d) • Problem 2 • With higher “mbias”(=2mA/hybrid), some VA output showed oscillation. (5/17) • With lower mbias(0.9mA/hybrid), no oscillation. • Phenomena • Only on L4,L3-BW (3DSSDs half ladder) • No oscillation on L1,L2,L3-FW • Osc. occur on P and N simultaneously. • Investigation • Grounding Endring MAMBO • Capacitor btw hybrids : check with L3 ladder. • Offset voltage ⇒no effects

  5. With mbias=2mA/hybrid outA difference outB f=1.95MHz

  6. offset N=+40V P=-40V DSSD DOCK Hybrid

  7. Capacitor btw. hybrids disconnected • Mbias=2.0mA

  8. Capacitor btw. hybrids disconnected • Lower mbias

  9. Solution(?) • Setting for Prebias (3 bits) • Bit 1 must be 0!! • “110” must be the largest Prebias value. • Still unstable at single channel mode • Some hybrids oscillate sometimes. • Other parameters should be tuned • Trigger performance is not • Range of parameter tuning is restricted for VA and TA

  10. outA Tp=650ns Long tail outB

  11. Typ mbias(2mA) • Prebias=“100” • Others are “fast” parameter • 1 hybrid on L4 shows huge noise.

  12. Schedule (for next two weeks) • Full system • L1.5 integration (Ziegler) Continue • VA tuning (Matsumoto) 5/22. • TA threshold tuning ( Ishino, Kaneko)5/23～6/1 • Cosmic ray run should be resumed ASAP for trigger integration and final system check. • 5/25- Test run • 6/2- Cosmic run • 8 hour/day • TA tuning, Trigger integration, slow control test in parallel • 1/10 system • TA study, trigger integration(Hazumi, Nakadaira) • Laser scanning for test sensor (Tsuboyama)

  13. -3V analog ～5A 0.5W Output -3.3V 6A needed • 0.5W resistor is too small • Limited ～ 4A • Replaced to 1W ⇒ OK up to 6A • Krakow agreed to the modification • Recommend to use larger power consumption resistor Regulator(1.4A) Input -7.5～-9.5V

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