Development of a pixel readout chip compatible with large area coverage

Abstract A second version of the Omega pixel readout chip has been developed in order to make it compatible with large area coverage. Specific features of the new chip include a reset which can be applied immediately following a “false” trigger, an improved minimum strobe time of ∼ 100 ns, a readout clock rate of ∼ 20 MHz and tri-state buffers on the output data lines. The excellent performance figures of the first chip for noise (100 e rms without detector and 170 e rms with detector) and power consumption (30 μW/pixel) have been maintained. We demonstrate how with solder bump-bonding we can create hybrid “ladders” which hermetically cover an area of ∼ 5 mm × 50 mm. Potential problems of electrical matching and yield have been addressed and procedures are in place for selecting only “good” readout chips for mounting.