Local Control of a HPD Power Supply Module

L.P. Dimitrov, B.B. Kunov

Institute for Nuclear Research and Nuclear Energy, Bulgaria

he local control and monitoring of an 8-channel power supply module is described. The module consists of four high voltage /HV/ channels and four bias voltage /BV/ channels and is provided to supply four Hybrid Photodiode /HPD/ detectors. The control and monitoring hardware is implemented in three Xilinx XC9536XL CPLD – master, HV-slave and BV-slave. The master is connected to a main /crate/ controller via a bi-directional serial bus and to the slaves via serial connection. The control instructions issued by the main controller and executed by the modules are: address selected channel; enable/disable a addressed (or all) channel(s); write value to a addressed (or all) channel(s); perform conversion of a addressed channel parameter /voltage or current/, applied to an on-board serial 12-bit ADC. The monitoring instructions are: read converted in the ADC value and voltage or current protection status; read interlock status. The HV-slave monitors the HV channels and the BV-slave monitors the BV channels. The control functions are distributed in all three CPLDs.

The HV module is a basic unit of the Computer controlled power supply system for HPD photodetectors of the CMS Hadron Calorimeter /HCAL/.

[1] HCAL Technical Design Report. CERN/LHCC 97-31, CMS TDR 2, 1997.
[2] L. Dimitrov, B. Kunov, I. Vankov. Computer controlled power supply system for HPD photodetectors. Proc. of the JINR XVII Intern. Symp. on Nucl. Electronics, Varna, Sept. 1997, p. 34.