  A versatile and reconfigurable ASIC is presented, which implements two
different concepts of low level trigger (L0) for Cherenkov telescopes: the
Majority trigger (sum of discriminated inputs) and the Sum trigger concept
(analogue clipped sum of inputs). Up to 7 input signals can be processed
following one or both of the previous trigger concepts. Each differential pair
output of the discriminator is also available as a LVDS output. Differential
circuitry using local feedback allows the ASIC to achieve high speed (500 MHz)
while maintaining good linearity in a 1 Vpp range. Experimental results are
presented. A number of prototype camera designs of the Cherenkov Telescope
Array (CTA) project will use this ASIC.
