3-in-1 Revisions Since Design Review
Note: The current 3-in-1 design is Version 3.1 and this will be used in the 1999 test beam studies. Version 2.1 was used for test beam studies in 1998.
L and C values were optimized to refine the pulse shape and compensate for parasitic capacitances of the PMT and op amps.
Alternative choices for the clamping amplifiers U14 and U15 were investigated for reduced cost but because of radiation sensitivity we reverted to the component choice used for Version 2.1; namely, CLC502 and CLC501.
The EPLD, U4, was changed from EPM7064SLC44 to EPM7064STC44 for reduced cost, smaller size and acceptable radiation tolerance.
The DAC, U5, was changed from MP7533 to MP7633JS for improved radiation tolerance.
Op amp U7 was changed from OPA420 to OPA4277UA for improved radiation tolerance.
The switches U10 were changed from DG412 to DG611 for improved radiation tolerance.
An output buffer, U19, was added for more reliable operation.
Details of the feedback loop on the gated op amps U17 and U18 were changed for better isolation.