A biquadratic continuous-time filter designed to operate as signal shaper in the read-out electronics of elementary particles experiments has been implemented in 2 /spl mu/m BiCMOS technology. The cell synthesizes a semi-Gaussian response with a shaping time adjustable in the range 18-30 ns. The power consumption is 1.25 mW from a single 5 V power supply. The integral nonlinearity is within 1% for an input signal amplitude up to 200 mV. The chip active area is 0.08 mm/sup 2/. The measured input referred noise is 50 nV//spl radic/Hz.