Front-end measurements of the new prototype of versatile MPGD read-out chip SALSA

Abstract The SALSA chip is a future versatile MPGD readout ASIC for the tracker of the ePIC experiment at the EIC currently under construction. The ePIC specifications state that SALSA should acquire charges up to 250 fC with a noise below 0.5 fC. SALSA1 prototype is dedicated to the analog front-end and ADC validation. Two different front-end architectures were tested and compared to help select the best one for the next iteration. Measurements of the gain, noise, resilience to saturation and to temperature variations have been conducted on several ASICs. SALSA1 implements four dynamic ranges and eight peaking times. Typical measured gains for ePIC configurations and with a peaking time of 250 ns are 2.6 mV/fC or 3 mV/fC, depending on the channel architecture. The measured noise stays below the 0.5 fC specification for peaking times down to 150 ns and so fulfills the ePIC requirements. Measurements also confirmed the expected sensitivity of the first pole zero compensation architecture considered to temperature variation from 5 to 65°C.