Digital mammography X‑ray machines (molybdenum target machines) represent the gold‑standard equipment for early screening and diagnosis of breast cancer. Featuring high‑contrast imaging of breast soft tissue, they can accurately detect microcalcified lesions smaller than 0.1 mm in diameter and serve as core medical devices enabling early detection, early diagnosis, and early treatment of breast cancer. The high‑voltage power supply is an essential power component of digital mammography machines. It provides a stable DC high voltage for the X‑ray tube to generate low‑dose, high‑contrast soft X‑rays. Its ripple suppression capability, bipolar switching speed, and long‑term thermal stability directly determine the imaging contrast of breast soft tissue, the detection rate of microcalcified lesions, and the accuracy of clinical diagnosis. Current high‑end mainstream digital mammography machines require the high‑voltage power supply to achieve an output voltage range of 20 kV~50 kV, output ripple below 0.1%, tube voltage control accuracy better than ±0.2%, bipolar high‑voltage switching time less than 20 ms, and voltage overshoot below 0.5% during switching. Failure to meet these criteria will cause distortion of the X‑ray energy spectrum, degradation of soft‑tissue imaging contrast, inability to identify tiny calcified lesions in early breast cancer, and missed optimal diagnostic opportunities. Restricted by traditional topologies, conventional high‑voltage power supplies for mammography machines suffer from high output ripple, slow bipolar switching speed, large voltage overshoot during switching, and severe thermal drift during long‑term operation, failing to satisfy the stringent imaging requirements of high‑end digital mammography equipment. The design must strictly comply with IEC 60601‑2‑65 Medical electrical equipment — Part 2‑65: Particular requirements for the basic safety and essential performance of mammographic X‑ray equipment and stereotactic localizing devices, as well as GB 9706.24 Medical electrical equipment — Part 2‑45: Particular requirements for the basic safety and essential performance of mammographic X‑ray equipment. It must also meet the technical specifications for Class III medical device registration under NMPA. Addressing the core clinical requirements and technical challenges of high‑voltage power supplies for digital mammography machines, this methodology establishes a comprehensive general technical framework covering topology design, low‑ripple output optimization, fast bipolar switching control, thermal stability compensation, and medical safety compliance design. It accommodates the high‑voltage power demands of various digital mammography devices and provides standardized design guidelines for domestic substitution and grassroots popularization of breast screening equipment. Focusing on the key design challenges of low‑ripple output and fast bipolar switching in mammography applications, this methodology adopts a dual symmetrical high‑frequency resonant inverter topology as the universal framework, with independent positive and negative high‑voltage output channels sharing a common high‑precision low‑temperature‑drift reference source and fully digital control unit. This ensures independent controllability of positive and negative outputs while achieving high‑precision synchronization, fundamentally overcoming voltage imbalance and slow switching inherent in traditional single‑ended topologies for bipolar operation. A full‑bridge LLC resonant inverter is selected because it enables zero‑voltage switching (ZVS) on primary power switches and zero‑current switching (ZCS) on secondary rectifiers across wide load ranges, delivering low switching loss, low output ripple, and low electromagnetic interference — fully matching the low‑ripple and high‑stability demands of mammography systems. Four core design principles are followed. First, to accommodate wide voltage and wide load variations in mammography applications, resonant parameters are optimized through fundamental harmonic analysis combined with time‑domain simulation. The resonant frequency is designed between 120 kHz and 200 kHz with a normalized gain of 0.8~1.3 and a quality factor Q of 0.6~0.8. This maintains soft switching throughout the full output voltage range of 20 kV~50 kV and full load range of 10 mA~100 mA, avoiding increased switching loss, EMI, and ripple caused by hard switching. Overall efficiency exceeds 95%, while heat generation under high‑frequency operation is greatly reduced, laying a solid foundation for low‑ripple output and long‑term stable operation. Second, the two inverter units adopt fully symmetrical circuit layouts and component selections with identical PCB routing, component parameters, and drive circuits, sharing the same high‑precision low‑drift reference source. This guarantees fully matched control accuracy, response speed, and thermal characteristics between the two channels, preventing output imbalance and voltage overshoot during bipolar switching. Third, the high‑voltage transformer features an integrated symmetrical dual‑primary and dual‑secondary structure. The two primary windings correspond to the two inverter units, while the two secondary windings feed the positive and negative high‑voltage outputs. Layered interleaved winding ensures a coupling coefficient ≥ 0.998 and leakage inductance ≤ 3 μH. Advanced multi‑layer insulation with polyimide film and vacuum epoxy potting satisfies double insulation and high‑voltage withstand requirements for medical equipment. Fourth, integrated input EMI filtering, soft start, and inrush current limiting circuits ensure electromagnetic compatibility, preventing interference with other sensitive medical devices in the hospital environment — especially flat‑panel detectors in the same room — which could degrade imaging quality. Low‑ripple output optimization is central to this methodology. To meet strict spectral purity requirements for X‑rays in mammography, ripple suppression is realized through topology improvement, multi‑stage passive filtering, and active ripple cancellation. At the topology level, ripple generation is minimized at the source. A symmetrical four‑stage voltage multiplier rectifier is adopted. Compared with conventional single‑ended multipliers, positive and negative ripple components are out of phase, achieving over 50% ripple cancellation through superposition while reducing voltage stress on each rectifier and capacitor to one quarter of the total output, simplifying high‑voltage insulation and lowering noise. Silicon carbide Schottky diodes are used on the secondary side to eliminate reverse recovery effects, removing voltage spikes and high‑frequency noise originating from conventional fast‑recovery diodes. Optimized low‑parasitic PCB layouts with laminated busbars minimize high‑voltage power loop length, limiting parasitic inductance within 5 nH and suppressing high‑frequency oscillations and switching spikes. In multi‑stage passive filtering, full‑band ripple attenuation is achieved via three cascaded π‑type high‑voltage filter networks. The first stage uses large high‑voltage film capacitors to suppress low‑frequency ripple below 100 kHz. The second stage employs small high‑frequency ceramic capacitors for mid‑frequency ripple from 100 kHz to 10 MHz. The third stage uses feedthrough capacitors to eliminate high‑frequency noise above 10 MHz. All filter components adopt ultra‑stable low‑ESR low‑temperature‑coefficient devices: polystyrene high‑voltage film capacitors with temperature drift ≤ 30 ppm/°C, NP0 ceramic capacitors with drift ≤ ±30 ppm/°C, and high‑precision non‑inductive metal‑film resistors with drift ≤ 10 ppm/°C. This ensures consistent filtering performance across the full operating temperature range, restricting peak‑to‑peak high‑voltage ripple within 0.05% — far better than the industry standard of 0.1%. In active ripple suppression, residual ripple is dynamically counteracted using a high‑speed operational amplifier based active cancellation circuit. High‑voltage differential probes and high‑speed ADCs continuously sample ripple components, which are phase‑inverted, amplified, compensated, and injected back into the high‑voltage output path to cancel residual fluctuations, improving ripple attenuation by more than 6 dB and guaranteeing ripple below 0.08% under all voltage and load conditions, preventing spectral broadening and degraded imaging contrast caused by high ripple. Fast bipolar switching control enables compatibility with dual‑target mammography systems for rapid polarity changes corresponding to molybdenum, rhodium, and tungsten targets. An FPGA‑based overshoot‑free feedforward plus closed‑loop composite control algorithm eliminates the slow response and large overshoot of traditional PID control. Three core principles apply. First, pre‑stored feedforward parameters including target high‑voltage values, drive timing, and filament current compensation for each target material are immediately loaded upon a polarity switching command. Drive parameters, reference voltages, dead time, and resonant operating points are pre‑adjusted to avoid integral saturation and delay in conventional closed‑loop control, inherently suppressing switching overshoot. Second, high‑speed microsecond‑level closed‑loop calibration continuously samples positive and negative output voltages and tube currents via 24‑bit high‑precision ADCs at 500 kHz, performing iterative corrections every 1 μs during switching to ensure smooth transient transitions without overshoot or voltage drop, enabling rapid stabilization after switching. Third, dual closed‑loop linkage of tube voltage and tube current synchronizes filament current adjustments during polarity transitions to compensate for space charge effects and target‑induced current variations, keeping tube current fluctuation within ±0.8%, stabilizing X‑ray dosage, and preventing motion artifacts and blurring. With this control strategy, full‑range bipolar switching can be completed within 12 ms with voltage overshoot controlled below 0.3% and settling time shorter than 8 ms, significantly exceeding the 20 ms industry benchmark and fully supporting fast exposure in dual‑target mammography machines. Thermal stability and long‑term reliability form critical supporting elements of this methodology. Comprehensive temperature compensation and reliability design ensure stable continuous operation. Full‑range thermal compensation employs multi‑point temperature monitoring of high‑voltage transformers, rectifiers, filter capacitors, reference circuits, and power devices. An FPGA‑embedded thermal drift model dynamically adjusts reference voltages, drive parameters, and closed‑loop gains to compensate for component variations with temperature. Within an ambient temperature range of 0 °C~40 °C, tube voltage accuracy remains better than ±0.15%, tube current accuracy better than ±0.6%, and voltage drift below 0.15% after 8 hours of continuous operation, meeting long‑term stability requirements for clinical use. Medical safety compliance strictly adheres to the IEC 60601 series. Double insulation provides over 100 kV isolation between high‑voltage circuits, low‑voltage control sections, and patient accessible parts. Patient leakage current is limited below 10 μA and equipment leakage current below 100 μA, well below regulatory limits. A seven‑level redundant protection scheme includes input over/under voltage protection, output overvoltage protection, overcurrent/short‑circuit protection, overtemperature protection, arcing protection, filament open‑circuit protection, and anode overheating protection, all implemented with hardware and software dual redundancy and response times faster than 1 μs. Safety interlocks with the main mammography system instantly cut high voltage upon any fault to ensure absolute safety for equipment, patients, and operators. Integrated kV/mA adaptive control automatically optimizes tube voltage and current according to breast thickness and density, enabling low‑dose high‑definition imaging with single exposure dosage below 50% of national limits, significantly reducing patient radiation exposure. Electromagnetic compatibility fully complies with GB/T 18268.1. The entire system adopts double shielding, fully enclosed shielding for high‑voltage sections, and multi‑stage EMI filtering at input and output terminals. Radiated and conducted emissions are far below standard limits, while ESD, EFT, and radiated immunity reach Level 4 or higher, ensuring stable operation in complex hospital electromagnetic environments without interfering with weak signal acquisition in flat‑panel detectors and preserving image quality. Addressing the core clinical demands and technical bottlenecks of high‑voltage power supplies for digital mammography machines, this methodology delivers a complete technical solution covering topology innovation, ultra‑low‑ripple optimization, fast bipolar switching control, and medical safety compliance. It resolves the longstanding issues of high ripple, slow polarity switching, and poor thermal stability in conventional power supplies. Symmetrical voltage multiplication and multi‑stage filtering achieve ultra‑low ripple within 0.05%. Feedforward‑closed‑loop composite control realizes overshoot‑free bipolar switching within 12 ms. Full‑range thermal compensation maintains voltage accuracy within ±0.15%. The solution fully satisfies the strict imaging requirements of high‑end digital mammography equipment, supports widespread domestic deployment, and provides core technical foundations for localized manufacturing of early breast cancer screening devices.