1. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague1 Electronics part of AHCAL calibration system ECFA meeting at Warszawa

2. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague2 Proposal for calibration system Fast LED driver is needed for fast photodetectors… A tunable calibration light in the range 0 to 100MIP Simplification of the optical system: one LED -> one side emitting fibre, one row of scintillator tiles See Jara’s talk Optical part of AHCAL calibrator

3. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague3 Two scenarios of calibration system for EUDET AHCAL 1.Side emitting fiber for one raw, QRLed driver sitting on the side of module (endcap) 2.QRLed driver is sitting at HBU above the scintillator

4. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague4 Side emitting fiber version QR driver + LED 24*3cm² area needed at the main PCB 24 fibers

5. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague5 Scenario with QRLed driver by scintillator One LED, one QRLed driver at HBU Signals needed:  T-calib  V-calib (single ended)  power +12V This figure is been used by Riccardo Fabbri’s talk QRLed driver will be placed here around

6. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague6 Electrical block diagram of the Calibrator QRLED 1 T-calib V-calib Power regulator QRLED 24 LED1 LED24 +12V Optical taps - notches - drops # of elements compensate exp attenuation

7. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague7 QR LED driver, basic parameters Fixed pulse width 2 ÷ 10 ns LED is an integral part of QR driver Cosine waveform reduces elmag. x-talk PCB footprint 2 ÷ 3 cm² Easy power-pulsing

8. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague8 PIN PD response to UVLED LED current 1V => 1A PIN

9. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague9 Principal schema of QRLed driver A A LED

10. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague10 Toroidal inductors, ~ 30nH All inductors has Non-magnetic core No sensitivity to external mag. field L1 L2 L3

11. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague11 Toroidal inductors - parameters Inductors toroidals non magnetic core turnsL [nH] @100kHzQ @100kHzL [nH] @50MHzQ @50MHzcore L16321.6 PE L25201.7*53nH*95PX L37251.8*56nH*73PX non mag core Polyethylen PE OD = 7mm, ID = 4mm, h = 1.6mm non mag core Pertinax PX OD = 7mm, ID = 4mm, h = 1mm stars ** means inductors used 2.5cm terminals to measure Q @ 50MHz it adds about 20nH to total inductance

12. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague12 Toroidal inductor soldered

13. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague13 Toroidal inductor soldered See thickness of PCB and inductor

14. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague14 LED current Max amplitude 1A

15. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague15 LED current zoomed 2ns/div 1A peak

16. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague16 Linearity test - preliminary

17. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague17 Conclusion Inductor has been changed from loop to toroidal structure  better magnetic isolation 2 scenarios for calibration system –QRLed driver at HEB (endcap)  fibers needed –QRLed driver in detector on HBU  no fibers At the next HCAL DESY meeting we would like to start the discussion about the integration It is a part of the EUDET task Multichannel LED calibration prototype

18. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague18 Backup slides

19. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague19 LED current View of the LED pulse for a middle amplitude (1.0 A) Measured with 1GHz voltage differential probe and 1GHz scope TDS4104 at 1Ω smd resistor 4ns/div 0.5A/div

20. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague20 In wider time scale PIN

21. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague21

22. ECFA, JUN10, 2008Ivo Polak, IPASCR, Prague22 In wider time scale, increase of the amplitude PIN 2mV/div