V. TEST AND CHARACTERIZATION
A. Experimental Setup
In order to test the presented chip, the latter was packaged
in a PGA 144. A PCB board has been designed to generate
the different bias voltages and power supply ranging from
0 to 3.3 V, control the shape of the (TX) signal and generate
the ramp of the SS-ADC. The chip is mounted on the board
through a socket over which an optical objective is assembled.
the board is powered with an external 5 V source and
encompass power supply filters for low noise requirements.
The board is connected to a PXI rack with two FPGAs that,
on the one hand generate the digital control signals, and on
the other receive the digital and analog outputs of the board
coming out of the chip. The analog input of the FPGA has
an integrated 14 bit ADC with an LSB of about 200μV.
It was used to characterise the pixels using the analog output
mode. The FPGAs are programmed with a computer using
LABVIEW©. For measurements requiring the variation of the
input light, a simple led powered with a low noise tunable
voltage source was used. The LED were fixed at the end of a
dark tube put on top of the imager.