An updated and revised version 3.2 of the MuonPi HAT PCB is currently in production at JLCPCB including partial mounting of components and expected to arrive within the next two weeks. The revision is intented to be entirely compatible (100% software compatible, downward compatible wrt hardware) to the previous one. The changes in overview:
- The pads of the combined u.Fl/SMA receptacle footprints are placed closer towards each other. In this way GND pins of the u.Fl receptacles overlap more appropriately with the respective pads on the board.
- At the output of the peak detector (as optional plug-on module) a second, faster SPI-ADC MAX11105 was integrated which can sample the amplitude signal much faster (max 2MSPS) than the ADS1015/ADS1115. This will help to reduce the complexity of the PD module in the future. Further experiments with an improved amplitude measurement are foreseen at the beginning of 2022.
- The field in the silk screen foreseen to write the serial number into, was enlarged.
- As an alternative to the temp sensor IC U403 (originally foreseen was the LM75) a pin- and function-wise compatible MIC184 may be mounted. This IC additionaly provides the connection of a remote temperature diode at its pin 5. When utilizing this option, connector X6 can be converted from a bias voltage output (in parallel to X5) to a remote temp sensor input through omission of R420/R517 and mounting of R518. As a remote sensor, any p-n-junction of a diode or a transistor can be used. Applications for this use case still have to be worked out. However, the temperature-gain compensation of the SiPM can be potentially realized through such a circuit when placing the sensor diode/transistor close to the sensor on the SiPM PCB.
Stay tuned for more updates when the boards are being tested.