BeetleFE 1.1

BeetleFE 1.1 is a test chip containing improved preamplifier/shaper circuitry of the Beetle chip.

It contains three different blocks of preamplifiers and shapers that follow the basic RD20 approach of a folded cascode charge sensitive preamplifer followed by an active CR-RC shaper and a buffer. All frontend channels of BeetleFE 1.1 use an NMOS input transistor and a PMOS feedback transistor in the preamplifier. Design goal for this chip was to develop a front end with faster shaping and increased rate capability than the BeetleFE1.0 to cope with higher detector occupancies.

The three blocks differ as follows

• Block 1 consists of two "Set4" channels. The difference beween the two channels results from additional substrate contacts added on Beetle1.0, which were not present on the original BeetleFE1.0.
• Block 2 consists of 5 frontend channels with different preamplifier and shaper feedback circuits.
• Block 3 is identical to Block 2, except for the modified bias circuitry.

The picture shows the layout of the chip. The three groups of frontend channels are clearly visible.

The next picture shows the padlayout of the chip.