High voltage regulation circuits with low voltage sensing and inrush current limiting functions for solid-state detectors in PET

The high voltage (HV) regulation circuit, with a low voltage (LV) sensing and inrush current limiting functions, can be implemented with silicon-photosensor detectors in positron emission tomography (PET) scanners. The targeted application is for silicon detectors such as SiPM or APD based MR/PET systems. The low voltage DC power supply sensing and inrush current limiting functions in the circuit provide the necessary protection to the silicon photosensors and subsequent front-end electronics, including charge-sensitive preamplifiers in APD detectors, and voltage-sensitive or current-sensitive preamplifiers in Sil´M detectors. The circuit eliminates the previous power supply sequencing requirements of (1) powering up low voltage power supply (LVPS) before the high-voltage power supply (HVPS); (2) power down HVPS before the LVPS; (3) slow ramping during power up (down). The circuit automatically turns off HV whenever the LVPS is unavailable due to unanticipated circumstances such as power supply malfunction, power line glitch, or power up in the wrong sequence. The high voltage regulation function provides the high level power-supply-rejection-ratio (PSRR) and high stability. It stabilizes and delivers a constant high voltage potential from a relatively large dynamic range input of HV power supply (HVPS), unaffected by SiPM or APD current fluctuations due to incident light density variance. The circuit is designed and simulated with SPICE, then fully evaluated with prototype printed-circuit boards (PCBs). The circuit achieves PSRR attenuation up to -68 dB or ±10 ppm, and maintains the high voltage potential within ±5 mV with nominal negative high voltage of-SOD volt.