pixel testing lhcbuk 10.01.01

1
Pixel Chip Testing
S. Easo, RAL 10-1-2001

• Current Status of the Pixel Chip Testing.
• Plans for an LHCb Test Setup at CERN.

2
Current Status

• On the IC tester the chip is proved to be
  functional.
• This setup is mostly software controlled. The
  only
• external hardware needed is the pixel chip
  glued and
• bonded on a board and a couple of power
  supplies.
• IC tester is in high demand at CERN
• Not suitable for high statistics tests.
• For detailed chip characterization another Test
  Setup is used

• A Test Setup using VME is working in ALICE.
• This uses different boards which are custom made
• within the CERN-ALICE group.
• I am copying this setup and its software for
  LHCb.

3
Current Pixel Test Setup
VME
PC
P I L o T
M X I
JTAG Controller
Con- figu- ration
Fast Controls
Data
Power Supplies
Readout Interface
5V,-5V analogue, 5V digital
Board to which the Pixel chip is glued and Bonded.
Pixel Chip
4
Pixel Test Setup

• Pilot Board
• Provides the Fast Control Signals.
• Examples (1) Strobe ( first level trigger)
  is a signal to
• write data
  to the pixel chip FIFOS.
• (2) Next Event Read is a
  signal to
• read data
  from pixel chip FIFOs.
• (3) Test_Pulse To trigger
  the injection of test charge
• 
  into pixel preamplifiers.
• Acquires Data and performs zero suppression.
• Current version works at 10 MHz. It can be
  modified to 40 MHz.

• Readout Interface Board (from Mike Burns)
• Provides Power, Analogue bias etc.
• Converts LVDS lt----gtGTL . Pixel chip
  uses GTL.
• Is expected to be replaced by the PIXIE board
  in the future,
• for testing the pixel chip on carriers
  and tubes.

5
Pixel Test Setup

• JTAG Controller
• Commercially produced board.
• Used for the slow controls Setup Thresholds,
  Configuration etc.
• ALICE uses a version mounted on the VME crate. I
  use the
• PC version since it is the only one available
  for now.
• This controller is verified to be functional,
  during last month.

Data path Pixel Chip--gtReadout
Interface--gtPilot board--gtPC.
Readout Software Labview for now. Can be
translated in the future.
Example of Measurement S curve to estimate the
noise
and threshold of Pixel channels.
6
Plans and Summary

• For the LHCb setup, all components except the
  Readout Interface
• Board are available. This board is undergoing
  tests and is
• expected to be available in a few days.
• I plan to write the software needed for the
  characterization of the
• chips and perform the characterization on the
  bare chips glued
• on the board.
• This setup is expected to be a prototype for
  LHCb specific
• tests on the chip. We should be able to use
  this, to test
• chips mounted on carriers, tubes etc. Once
  functional, we can
• copy this setup for large scale HPD testing.