1. HB LED Pulser Boards By Michael Miller The University of Iowa

2. HB LED Pulser Boards HB Pulser board has the same mechanical format as the HB QIE Card. Pulser is controlled through the CCA (channel control) ASIC via the RBX Serial Bus. There are 2 semi independent pulsers on the board. Output amplitude is between 1.4 & 5.2 V. LED output light profile is similar to the signal from the megatiles. Board provides 5V biasing for up to 6 independent PIN diodes. For the pulse amplitude the “Pedestal DAC” outputs are used. Vout=5.2V – N*15.3mV where N is the 8 bit Pedestal DAC setting. Timing for the two LED pulsers is derived from the “Test Pulse” CCA output. This 25 ns signal can be masked for channels A and B independently and timed to any bunch crossing of the LHC orbit. Two external inputs facilitate pulser testing and make it possible to work without TTC infrastructure. There were several minor changes after the first prototype: 2 extra CCA outputs are used to allow individual triggering for Pulser A and Pulser B. Maximum output DAC voltage was changed from 2.55V to 3.9V to increase the dynamic range of the LED signal.

3. LED Pulser Board Block Diagram

4. Pulser Electrical Diagram

5. LED Connection

6. HB LED Pulser Board Prototype

7. HB LED Pulser Board Prototype output signal integral profile at different amplitudes

8. LED Pulser Board prototype output signal dynamic range.

9. HB LED Pulser Boards Production Design, manufacture, quality control and delivery done by The University of Iowa. 30 LED Pulser Boards delivered to FNAL ASAP, on August 2004. 110 LED Pulser Boards were tested at the University of Iowa and delivered to FNAL in Sept. 2004. The Pulser Boards are o.k. and give enough signal.

10. HB LED Pulser Boards Production