CARIOCA-0.25 /spl mu/m CMOS fast binary front-end for sensor interface using a novel current-mode feedback technique

We report on a very fast and low noise front-end, implemented in 0.25 /spl mu/m CMOS technology. The CARIOCA amplifier discriminator chip has input impedance of 10 /spl Omega/, in order to be compatible with sensors of large capacitance, and a peaking time of 14 ns. The conversion gain of 8 mV/fC remains almost unchanged up to a detector capacitance of 120 pF. A noise figure of 450e/sup -/ at zero input capacitance with a noise slope of 37.4e/sup -//pF, at a 2.5 V power supply, was measured.