BeetleFE 1.2

BeetleFE 1.2 is a test chip containing improved preamplifier/shaper circuitry of the Beetle chip.

It contains three different sets 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. 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 sets (top to bottom) differ as follows

• Set 2 consists of a single channel as implemented on the original BeetleFE1.0. It uses a PMOS input preamp with PMOS feedback transistor.
• Set 5 consists of 9 frontend channels with different preamplifier input transistors and shaper feedback circuits. It uses a PMOS input preamp with PMOS feedback transistor.
• Set 6 is the original Set 2 from BeetleFE1.0, except that the preamplifier feedback has been changed: The 2nd channel uses an NMOS input preamp with NMOS feedback transistor.

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.