4-chip module on pixel stave(let) Joseph Finley 1 November 2013 - - PowerPoint PPT Presentation

4-chip module on pixel stave(let)

Joseph Finley

1 November 2013

Pixel Stave at LBL

First Stavelet

• 5 tabs on one side and 4
• n the other side.
• Serial Power

Stavelet Fabrication

• Stavelet cables
• Aluminum power lines
• carbon foam, carbon face

sheets, aluminum spacer

• Cured in autoclave

Stave and Stavelet problems

In order to achieve the correct thickness on the end of stave card, 2 pcbs are joined together. To create vias, metal is flowed through the

• holes. This was not always successful, and some vias were open.

Some cables had no open vias while others had a majority After repairing all the vias on the stavelet there were still several problems:

• On the 5-tab side, the power is open on the first tab
• several traces have high impedance (~60 ohms)

FE-I4B 4 Chip Module

We recently received the 4 chip FE-I4B flex for serial powering and I have started creating a wire bonding diagram

FE-I4B Flex Layout

Tabs on the stave/stavelet only have 2 pairs of data output traces, while the 4 chip module needs 4 pairs. To work around this problem we will be using a multiplexing board

NTC CMD N CMD P CLK N CLK P

Power Ground

DOB N_1 DOB P_1 DOB N_2 DOB P_2 NTC

HV 2 HV 1

Multiplexing Board

LVDS data Receiver 2-1 CMOS mux LVDS clk Receiver Buffer/Inverter to create differential pair Some difficulties in designing the multiplexing board was the limited space on the flex to place the board, as well as the limited power supply (< 2.5 V across FE-I4B) for use with the discrete chips on the mux board.

Multiplexing Board Setup

Test Board was originally designed to be used on a 2-chip or 4-chip module, but because we currently

• nly have single chip cards, I had

to copy the output from the chip to where the second output would be. I tried to copy command and clock signals to a second single chip card but reflections distorted the signals too greatly

To the Single Chip Card To USBpix

STcontrol software

• Using a version of

STcontrol created by Johannes Agricola

• This version allows for

parallel readout of chips as well as multiplexing

• ptions

First Results using a Single Chip Card

Analog Scan Single Chip Muxed Chip

First Results using a Single Chip Card

Digital Scan Single Chip Muxed Chip

Future plans

• Figure out problem with digital scan using

mux board

• Bonding diagram for 4-chip module
• Adapter board for 4-chip module to test off

the stave

Questions