XP Power Supply Technical Guide

Analysis of Core Technology Modules

(1) Basic Theory of Power Supply

Technical points, core content, key parameters/standards

Power type linear power supply: low noise (suitable for audio equipment), low efficiency, large size;

Switching power supply: High frequency switching (200kHz-1MHz), high efficiency (up to 91%), small size, linear power supply efficiency<60%; Switching power supply efficiency 75% -91%

Topology flyback converter (≤ 150W), forward converter (100-300W), half bridge (150-1000W), full bridge (>1000W), boost converter (PFC application), flyback converter has high ripple current; The full bridge converter has the highest power density

Distributed Power Architecture (DPA) front-end power supply → intermediate bus → load point DC-DC converter, supports hot swapping, redundant backup intermediate bus voltage 48VDC, allows ± 10% fluctuation

(2) Key technologies for input design

Power source:

AC power supply: single-phase (85-264VAC), three-phase (star/delta connection), global frequency 50/60Hz

DC power supply: battery (lead-acid/NiCd/NiMH/Li ion), DC generator (12/24/48VDC)

Input protection:

Surge/transient protection: GDT (gas discharge tube), MOV (metal oxide varistor), compliant with EN61000-4-5 (± 2kV common mode)

Surge current limit: NTC thermistor, cold start surge current 30-40A (continuous 1-2ms)

Reverse polarity protection: series diodes (no fuse), parallel diodes (fuse protection)

Harmonic suppression:

Passive PFC: suitable for ≤ 300W, power factor 0.5-0.6

Active PFC: suitable for>100W, power factor>0.9, compliant with EN61000-3-2 Class A/B

Grounding design:

Functional grounding (FE): No safety function; Protective grounding (PE): Anti electric shock (Class I system)

Creepage/electrical clearance: basic insulation ≥ 2.0mm, double insulation ≥ 4.0mm (300VAC)

(3) Output key design technologies

Core parameters:

Output voltage: 3.3-60VDC (standard), series connection can be extended to higher voltages

Ripple noise: ≤ 50mV pk pk (3.3-9V models), ≤ 0.5% pk pk (other models), 20MHz bandwidth measurement

Adjustment accuracy: Line adjustment ≤ 0.1%, load adjustment ≤ 0.6%

Output protection:

Overvoltage protection (OVP): 115% -140% Vnom, automatic recovery/locking

Overload protection: constant current limit, constant power limit, hiccup mode, turn back current limit

Short circuit protection: Trip restart (hiccup mode), no risk of damage

Operation mode:

Series operation: requires constant current limitation and reverse diode protection

Parallel operation: active current sharing (error ± 10%), supporting N+M redundancy

Redundant operation: ORing diode, supports hot swapping, ensures continuous power supply

Status and Control:

Status signals: AC OK (power supply normal), DC OK (output normal), over temperature alarm

Control interface: remote switch, voltage programming (0-5V corresponds to 0-100% output), current sharing control

(4) Specialized product technology

Product Type Application Scenarios Key Parameters

UPS system critical load backup power supply online (0ms switching), interactive (2-10ms switching), offline (2-10ms switching), capacity 250VA-800kVA

DC/AC inverter DC to AC output waveform (sine wave/quasi sine wave), input 12/24/48VDC, surge capacity 20% -300% (continuous for 3-15s)

Frequency Converter Frequency Conversion (50/60/400Hz) Static Converter (AC-DC-AC), suitable for aviation electronic equipment

Static switch (STS) dual power switching time<1/4 cycle, efficiency>99%, no mechanical wear and tear

(5) Thermal Management and Reliability

Thermal management:

Heat dissipation methods: natural convection (≤ 100W), forced air cooling (100-2000W, 12-48CFM), bottom plate heat dissipation (high temperature environment)

Fan selection: Calculated based on power loss, formula: airflow (m ³/hr)=2.6 × power (W)/allowable temperature rise (° C)

Capacitor lifespan: For every 10 ° C decrease, the lifespan doubles

Reliability:

Failure analysis: bathtub curve (early failure → stable period → loss period)

MTBF calculation: MIL-HDBK-217/F standard, typical value 500000 hours (25 ° C)

Influencing factors: complexity (number of components), stress (temperature/voltage), device selection (universal reliability)

Regulatory and compliance requirements

Security certification:

IT/Industry: IEC62368-1, UL62368-1, EN62368-1

Medical: IEC60601-1 (BF/CF grade), leakage current ≤ 10 µ A (CF grade)

Asian markets: CCC (China), BSMI (Taiwan), PSE (Japan), KETI (South Korea)

EMC Compliance:

Emission limits: CISPR22 Class B (conduction), Class A (radiation)

Immunity: ESD (± 8kV air discharge), EFT (± 2kV industrial grade), voltage drop (30%/60%/95%)

Energy Efficiency Standards:

CEC 2008: No load power consumption ≤ 0.5W (<10W), ≤ 0.75W (10-250W), efficiency ≥ 0.85 (>49W)

EU Code of Conduct: No load power consumption ≤ 0.3W (<15W), ≤ 1.0W (60-150W), efficiency ≥ 0.9 (25-150W)

Military standards:

MIL-STD 461E/F: EMC Emission/Immunity

MIL-STD 1275: Vehicle Power Supply (25-33VDC)

DEF STAN 59-41: British Standard Military Power Supply

Engineering Practice and Technical Topics

Battery selection and sizing:

Type comparison: Lead acid (low-cost, heavy), Li ion (high energy density, requiring protection), NiCd (wide temperature range, toxic)

Capacity calculation: Constant current method (Ah=current x time), taking into account temperature derating (derating from 0 ° C to 80%) and lifespan factor (x 1.25)

5 technical topics:

Configurable power topology: based on 380VDC bus, supports 14 outputs, power range 450W-2400W

Small and efficient AC-DC design: resonant topology+synchronous rectification, efficiency up to 91%, power density 10.55W/in ³

Compact and flexible power supply: Fractional Turn Transformer (FTT), reduces cross regulation, supports 3.3-60VDC output

Synchronous rectification technology: MOSFET replaces diode, reducing losses by 44%, suitable for low voltage (3.3/5V)

Military COTS power supply: based on commercial modules, meets -40 ° C low temperature, MIL-STD compliance, cost reduction of 30%