An lpGBT subsystem for environmental monitoring of experiments

In this paper, the Low Power Giga Bit Transceiver (lpGBT)built-in system for environmental monitoring of the LHC experimentsis presented. Eight external analogue inputs and eight internalvoltages are multiplexed into an instrumentation amplifier withselectable gain, whose output is digitised by a 10-bit SAR ADC. Aprogrammable current source can be enabled for each external inputto implement resistance measurements. Internal channels are used tomonitor power supplies and the output of the temperature sensor. Theenvironmental monitoring system includes a precise 1 V referencevoltage source and a 10-bit voltage DAC. All blocks were designedand fabricated in 65 nm CMOS technology, fully characterised, andthe pre- and post-irradiation measurement results are presented inthis work.