Raman spectrometer is a molecular structure analysis instrument based on the Raman scattering effect. Featuring core advantages such as non-contact detection, non-destructive testing, rapid analysis, strong fingerprint identification capability and no need for sample preprocessing, it is widely applied in materials science, life science, food safety, pharmaceutical testing, environmental monitoring, geological exploration, criminal investigation, cultural relic identification and other fields, serving as the key equipment for modern molecular analysis and on-site rapid detection. Photomultiplier Tube (PMT) is the core optical signal detection component of Raman spectrometers. The intensity of Raman scattered light is generally only \(10^{-6}\)~\(10^{-12}\) of the incident laser intensity, belonging to extremely weak optical signals. With ultra-high gain of \(10^5\)~\(10^8\), ultra-low dark current and wide spectral response range, PMT has become the preferred solution for detecting weak Raman scattered light in Raman spectrometers. The high‑voltage power supply is an essential supporting component for PMTs in Raman spectrometers, providing high‑precision and widely adjustable high‑voltage bias for the cathode, each dynode and anode of the PMT. It usually requires 8~12 independent high‑voltage output channels with a total voltage range of 0~1500 V. Its wide-range adjustability, gain linearity, low-noise performance and long-term stability directly determine the detection sensitivity, dynamic range, signal-to-noise ratio and spectral resolution of Raman spectrometers. Raman spectrometers raise core design challenges for high‑voltage power supplies in terms of wide dynamic range. On the one hand, Raman spectrometers need to detect optical signals ranging from strong Rayleigh scattering to extremely weak Raman scattering, with light intensity variations exceeding 10 orders of magnitude. The PMT gain must be continuously adjustable within \(10^3\)~\(10^8\) by tuning the bias voltage, requiring the high‑voltage power supply to support full-scale continuous adjustment from 0 to 1500 V while maintaining excellent linearity, stability and low noise across the entire range. On the other hand, Raman signals are ultra-weak at the nanowatt or even picowatt level, demanding peak-to-peak output ripple ≤ 0.01%, voltage noise density ≤ 10 nV/√Hz@1 kHz, and full-range voltage control accuracy better than ±0.1%. Failure to meet these indicators will cause PMT gain fluctuation, sharp rise in dark count rate and decline in signal-to-noise ratio, making effective detection of weak Raman signals impossible. Traditional PMT high‑voltage power supplies adopt single-transformer multi-winding output or resistive voltage division topologies, suffering from narrow adjustable voltage range, poor full-scale linearity, excessive noise at low voltage and severe inter-channel crosstalk, which cannot satisfy the wide dynamic range detection requirements of Raman spectrometers. Relevant designs must strictly comply with standards including GB/T 36065-2018 *General Specification for Raman Spectrometers*, GB/T 34899-2017 *Test Methods for Photomultiplier Tubes*, and JJF 1734-2019 *Calibration Specification for DC High-Voltage Sources*, while meeting the core demands of Raman spectrometers for wide dynamic range, high sensitivity and low noise. Targeting the key application requirements and technical challenges of PMT high‑voltage power supplies for Raman spectrometers, this methodology establishes a full-process general technical framework covering wide dynamic range topology design, full-scale linearity optimization, full-link low-noise control, multi-channel low-crosstalk design and long-term stability control. It accommodates the PMT high‑voltage power demands of various micro-Raman spectrometers, portable Raman spectrometers and Fourier-transform Raman spectrometers, providing standardized design criteria for performance improvement and domestic substitution of Chinese Raman spectrometers. Addressing the core design challenges of wide-range adjustability, full-scale low noise and high linearity in Raman spectrometer applications, this methodology adopts the main architecture of **main high‑voltage wide-range precision regulation + multi-channel active voltage division following + full-digital adaptive closed-loop control**, combined with full-range noise optimization and linearity calibration. It fundamentally breaks the technical bottleneck of traditional power supplies that cannot balance wide-range adjustment with low noise and high linearity, achieving 0~1500 V full-scale continuous adjustment while maintaining outstanding linearity, low-noise performance and control accuracy, which fully meets the wide dynamic range detection requirements of Raman spectrometers. The design follows five core criteria: First, a two-stage topology of **main high‑voltage wide-range precision regulation + multi-channel active voltage division following** is adopted to realize wide-range adjustability, high linearity and low crosstalk from the architectural root. The main high‑voltage precision regulation unit generates continuously adjustable stable high-voltage DC of 0~1500 V, providing a highly stable voltage reference for subsequent multi-channel voltage division. It employs a two-stage structure of **front-stage isolated LLC resonant inversion + rear-stage high‑voltage linear regulation**. The front-stage LLC resonant inverter achieves electrical isolation and wide-range voltage boost; optimized resonant parameters deliver a normalized gain of 0.5~1.5, maintaining zero-voltage switching (ZVS) for primary switches and zero-current switching (ZCS) for secondary rectifiers across 20%~100% output range, with low switching loss and minor ripple. It converts 24 V low-voltage DC to adjustable high-voltage DC up to 1550 V. The switching frequency is set above 200 kHz outside the detection bandwidth to avoid harmonic interference with weak Raman signals. The rear high‑voltage linear regulator is critical for precision wide-range regulation, adopting a closed-loop circuit with high‑voltage series pass transistors and high-gain wideband error amplifiers to deliver exceptional ripple rejection and ultra-low noise. It ensures precise regulation from 0 to 1500 V with line regulation ≤ ±0.03% and load regulation ≤ ±0.05%. Adaptive biasing keeps the voltage drop across series transistors at approximately 50 V, ensuring regulation performance while reducing power consumption and heat generation to improve efficiency and long-term stability. The multi-channel active voltage division following unit divides the main high voltage into 8~12 independent outputs according to PMT dynode gain distribution. Each channel uses a high-input-impedance low-drift high‑voltage op-amp voltage follower matched with precision low‑drift resistor networks, providing accurate buffering and proportional control. Compared with passive resistor division, active following features ultra-low output impedance, eliminating voltage drop caused by tiny dynode load current and maintaining fixed proportional distribution and uniform PMT gain across the full adjustment range. All channels are fully electrically isolated with inter-channel crosstalk ≤ 0.01%, and proportional coefficients can be flexibly configured to adapt to different PMT models. Second, full-scale linearity and gain stability optimization adopts a three-tier guarantee scheme: **precision hardware matching + full-range software calibration + adaptive temperature compensation**, ensuring full-scale linearity error ≤ ±0.05% from 0 to 1500 V and excellent PMT gain linearity. At the hardware level, sampling and divider resistors adopt high-precision metal foil resistors with temperature coefficient ≤ 2 ppm/°C and tolerance ±0.005%, from the same batch with thermal aging to guarantee stable ratios. Low‑drift Zener references with TC ≤ 1 ppm/°C and long-term stability ≤ 5 ppm/1000 h provide ultra-stable benchmark voltage. At the software level, an FPGA-based fully digital control system performs no fewer than 20 calibration points across 0~1500 V, establishing segmented polynomial correction models stored in FPGA to dynamically adjust DAC references and eliminate non-linear errors in real time. Gain calibration is available by sampling PMT anode current to correct intrinsic gain non-linearity of the tube itself and ensure quantitative detection accuracy across full light intensity. Multiple high-precision temperature sensors monitor key components to build full-temperature drift models, dynamically compensating linearity deviations caused by temperature changes and maintaining linearity error ≤ ±0.1% within 0~50 °C. Third, full-scale low-noise optimization implements a three-tier noise suppression strategy: **source noise reduction + full-link multi-stage filtering + full-range noise tuning**, keeping peak-to-peak ripple ≤ 0.01% and noise density ≤ 10 nV/√Hz@1 kHz throughout 0~1500 V. At the noise source, the LLC inverter operates fully in soft-switch mode to eliminate voltage spikes and high-frequency noise; optimized transformer winding reduces leakage inductance and high-frequency oscillation; SiC MOSFETs and SiC Schottky diodes minimize device-level noise. A six-stage full-band filtering architecture covers the entire signal path: three-stage EMI filtering at the input; two-stage LC low-pass filtering after LLC inversion; π-type RC filtering before linear regulation with closed-loop bandwidth optimized to 100 kHz and PSRR ≥ 120 dB to suppress residual ripple below 10 μV; three cascaded π-type RC filters at the main output; independent RC filtering at the input and output of each active following channel; and on-chip decoupling near PMT pins to eliminate long-cable high-frequency noise. Adaptive filtering dynamically adjusts closed-loop bandwidth and filter parameters at low voltage, preventing noise deterioration caused by discontinuous switching and ensuring uniform low-noise performance across the entire voltage range. Fourth, the wide dynamic range adaptive control architecture adopts an FPGA-based fully digital dual closed-loop scheme with inner current loop and outer voltage loop. Adaptive PID dynamically tunes parameters according to set voltage and load current, eliminating overshoot, oscillation and slow response in wide-range regulation. Fast voltage adjustment up to 100 V/ms supports automatic gain tuning and spectral scanning without overshoot. Preset gain profiles allow one-click switching for different samples and detection scenarios, greatly improving usability. Fifth, high-reliability protection and anti-interference design provide comprehensive redundant safeguards against PMT damage from high voltage. Dual hardware/software overvoltage, overcurrent, short-circuit and overtemperature protection feature hardware response ≤ 1 μs for instantaneous cutoff during faults. Soft start rises slowly at 10 V/s to prevent dynode damage from voltage surge; slow voltage drop at shutdown avoids abrupt potential changes. Each channel has independent current limiting; vacuum interlock prohibits high voltage under poor vacuum to prevent PMT discharge. The whole machine adopts a fully sealed double-layer shield enclosure with inner permalloy for low-frequency magnetic shielding and outer aluminum alloy for high-frequency electric shielding; sensitive circuits use local shielding boxes with single-point star grounding to eliminate ground loops; all cables adopt double shielding to ensure stable operation without interfering with weak Raman signal acquisition. Long-term stability and spectrometer integration serve as core supports for continuous operation. Built-in periodic self-calibration corrects aging drift, ensuring 8-hour voltage drift ≤ ±0.05% and annual drift ≤ ±20 ppm. Optimized full-conduction thermal design ensures uniform temperature distribution to slow component aging. Modular configurations adapt to micro-Raman, portable and Fourier-transform Raman systems with customized low-power miniaturization or ultra-high-sensitivity low-noise upgrades. Standard communication interfaces (RS232, RS485, USB, Ethernet) enable seamless connection with spectrometer main control for remote tuning, real-time monitoring and interlock protection; synchronous triggering with lasers and detectors realizes coordinated gain adjustment and spectral acquisition to improve signal-to-noise ratio. EMC performance complies with GB/T 17626 Class B to avoid interference with weak optical signal detection. All key components adopt high-reliability industrial-grade selection with Class I derating; environmental cycling, aging and vibration tests verify an MTBF ≥ 50,000 hours for long-term laboratory operation. In summary, this methodology forms a complete technical framework covering wide dynamic range topology, full-scale linearity optimization, full-link low-noise control and long-term stability design, resolving the traditional contradiction between wide-range adjustment and low noise/high linearity. It achieves 0~1500 V full-scale continuous adjustment via two-stage topology and active voltage division, full-scale linearity error within ±0.05% via three-tier linearity guarantee, and ultra-low ripple within 0.01% via three-tier noise suppression. Fully compliant with the wide dynamic range detection requirements of Raman spectrometers, it is widely applicable to various Raman instrument platforms, providing core technical support for the performance improvement and domestic independent development of Chinese spectroscopic analytical instruments.