Monolithic Power Systems, Inc. · NASDAQ:MPWR
Monolithic Power Systems — Technical Presentation (October 2023)
42 slides from Monolithic Power Systems's technical presentation, October 2023
Slide 1: Understanding PFC and LLC Topologies
Understanding PFC and LLC Topologies October 2023 Webinar will begin at 5:00 PM CEST | 8:00 AM PDT | 11:00 AM EDT rev 20180504
Slide 2: Agenda
Agenda ▪ Understanding Power Factor Correction ▪ MPS Solutions for PFCs ▪ Understanding Resonant Power Conversion ▪ MPS Solutions for LLCs ▪ Q&A
Slide 3: What Is PFC?
What Is PFC? • PFC stands for Power Factor Correction • Power Factor (PF) is the ratio of active (real) power over apparent power: active power [W] PF = = apparent power [V ⋅ A] • Popular analogy
Slide 4: What Is PFC?
What Is PFC? • A PF of 1 corresponds to the resistor case: VIN IIN IIN VIN o The current is sinusoidal and in phase with the input voltage • A typical power supply has a PF below 1: VIN IIN VIN IIN o The current is not sinusoidal, and may be out of phase with VIN o Larger RMS current circulates in i
Slide 5: Why Is PFC Needed?
Why Is PFC Needed? If the PF is low, more power circulates in the input wires than is used by the actual load ➔ Risk of overheating of electrical wires • At home: 3x 300W equipment with PF = 0.5 ≥ 8 A The same with PF = 1 ≥ 4A 220 Vac Happy birds! • On the distribution lines: ➔ Utility companies pus
Slide 6: The Basic Concept of PFC
The Basic Concept of PFC Adding PFC The input current follows the voltage
Slide 7: PFC Modes of Operation
PFC Modes of Operation • Boundary-Conduction Mode PFC (BCM) or CrM (Critical-Conduction Mode) Best suited for power < 300W Simpler architecture Zero-voltage switching Higher RMS currents • Continuous Conduction Mode (CCM) PFC IL Ipk Best suited for power > 200W Iref Lower RMS currents n-1 n n+1 off_
Slide 8: PFC Modes of Operation: Multi-Mode PFC
PFC Modes of Operation • Multi-Mode PFC HR12xx CCM or BCM at high loads → Different DCM modes (discontinuous-conduction mode) under light loads to optimize efficiency CCM CF DCM VF DCM Constant frequency Variable frequency IL Ipk IL IL Iref ton’ off_cur_ref Iref off_cur_ref Iref off_cur_ref n-1 n n+
Slide 9: PFC Topologies
PFC Topologies Passive: Line Filter Large input inductor forces the current to be sinusoidal Valley Fill 2x filtering capacitors are charged in series but discharged in parallel Active: Flyback (low-power, single-stage: PFC + isolated regulation) Buck (not very common) Boost (most common for POUT >
Slide 10: PFC Topologies
PFC Topologies There are many more active PFC structures, most of them based on boost topology Their main purpose is to achieve the best efficiency possible for a given output power (and price point) For example: interleaved boost, bridgeless boost, Vienna rectifier, totem-pole, etc. Full-Bridge Rec
Slide 11: Agenda
Agenda ▪ Understanding Power Factor Correction ▪ MPS Solutions for PFCs ▪ Understanding Resonant Power Conversion ▪ MPS Solutions for LLCs ▪ Q&A
Slide 12: MPS PFC Roadmap
MPS PFC Roadmap Totem-Pole PFC HR1280 MPF32010 PFC + LLC Combo Full Digital PFC + LLC Full Digital TP PFC HR1210/1/3/5 CCM PFC CCM TP PFC Full Digital PFC + LLC CCM PFC HR1275 MPxxxxx Full Digital PFC + LLC BCM TP PFC BCM PFC MP44018A MP44017 BCM PFC, BCM PFC, Burst Standalone MP44010 MP44014/A Low
Slide 13: MP44018 Key Features
MP44018 Key Features • Valley Turn-On for Minimum Switching Loss 1 FB VCC 8 2 COMP GATE 7 • Input Feed-Forward (Mains Compensation) 3 MAINSIN GND 6 • Frequency Reduction to Reduce Switching Loss under Light-Load Conditions 4 CS ZCD 5 • Improved THD • Enhanced Dynamic Response SOIC-8 (5mmx6.2mmx1.7mm
Slide 14: MP44018 Enhanced Dynamic Response
MP44018 Enhanced Dynamic Response Enhanced Dynamic Response VBUS ICOMP No Load Full Load ISOURCE1(COMP) COMP GgM2m2 gM1 G m1 IL ISOURCE2(COMP) VFB_GM3 ISINK1(COMP) VFB_GM2 VREF FB Gg M3m3 VBUS ISINK2(COMP) Full Load No Load Nonlinear gm COMP ➢ Low gm (gm1) for better PF and THD in steady state ➢ Hig
Slide 15: MP44018 THD Improvement
MP44018 THD Improvement BCM (Constant-On-Time) DCM (Variable-On-Time) IL IL Operation Mode tON t tON tDMG tDT t VAC ( ) VAC ( ) IIN2 ( ) = t ON ( ) DC ( ) = VAC ( ) VAC ( ) 2L REQ2 Input Current IIN1( ) = t ON ( ) = 2L REQ1 t ON ( ) + tDMG ( ) DC ( ) = t ON ( ) + tDMG ( ) + tDT
Slide 16: MP44018 Efficiency
MP44018 Efficiency Efficiency Comparison Efficiency MP44014@120VAC MP44014@230VAC MP44018 MP44060@120VAC MP44018 MP44060@230VAC 100.00% 98.00% 96.00% 94.00% Efficiency 92.00% 90.00% 88.00% 86.00% 84.00% 0% 20% 40% 60% 80% 100% 120% Load ➢ Under light-load conditions, the MP440 8’s efficiency is sign
Slide 17: HR1275 Key Features
HR1275 Key Features General System Features: • Total < 85mW No-Load Power Loss (including PFC + LLC) • HV Current Source for Start-Up • Smart X-Capacitor Discharge when AC Dropout, Approved by IEC 62368 and IEC 60950 • Power Good (PG) Function FBP 1 16 CR • External Over-Temperature Protection (OTP)
Slide 18: HR1275 PFC Architecture
HR1275 PFC Architecture Input Pins: D3 LPFC D4 RNTC VBUS Pin Descriptions RO1 + Cbus AC input sense through an external LCM1 ACIN CX1 CX2 Q1 divider resistor B1 C1 RO2 D1 D2 ZCD RCS PFC valley & demagnetization time detect input. Connect to a PFC RCSP RGATE ZCD switch drain through a high-voltage RI
Slide 19: HR1275 240W Performance
HR1275 240W Performance Test Conditions: VIN = 85VAC, IOUT = 20A Test Conditions: VIN = 265VAC, IOUT = 20A BCM High Load CH1: GATEP CH3: VBUS CH4: IPFC Test Conditions: VIN = 265VAC, IOUT = 10A Test Conditions: VIN = 85VAC, IOUT = 10A DCM Light Load
Slide 20: HR121x Key Features
HR121x Key Features System: • Pin < 100mW at No Load, 12V Output • High-Voltage Current Source for Start-Up and Smart X-Capacitor Discharger • Power Good (PG) Function • UART Interface and GUI for Parameters Configuration PFC: • CCM/DCM Operation of Digital PFC (Max Switching Up to 250kHz) • High PF
Slide 21: HR121x PFC Control
HR121x PFC Control PFC Patented Average Current Control: - CCM for Heavy Loads - DCM for Light Loads (Improved Efficiency) - Digital PI Compensator - PI Parameters Can Be Configured via the GUI • Directly on the Board • In Real Time
Slide 22: Agenda
Agenda ▪ Understanding Power Factor Correction ▪ MPS Solutions for PFCs ▪ Understanding Resonant Power Conversion ▪ MPS Solutions for LLCs ▪ Q&A
Slide 23: Why Resonant Converters?
Why Resonant Converters? • When output power increases, classical and simpler structures become too inefficient o Hard switching of power switches When the switch is turned on while the parasitic capacitor is charged, losses can be high (scale up with switching frequency) → Zero-Voltage Switching (Z
Slide 24: What Is an LLC Resonant Converter?
What Is an LLC Resonant Converter? • The LLC is a series resonant converter: - The magnetizing inductance (LM) of the transformer is one of the resonating elements - The leakage inductance (LS) of the transformer also participates in the resonance - Series capacitance (CS) is added to ensure the res
Slide 25: What Is an LLC Resonant Converter?
What Is an LLC Resonant Converter? The LLC converter ensures soft switching under normal-load conditions: • Zero-voltage switching (ZVS) for the power switches (primary side) • Zero-current switching (ZCS) for the rectifying diodes (secondary side) It can operate at a high switching frequency to bui
Slide 26: Current-Mode LLC
Current-Mode LLC • Controlling the frequency of the LLC to regulate the output leads to complicated loop compensation • It can be made simpler by controlling the primary peak current cycle-by-cycle → current-mode control • By monitoring the voltage across the resonant capacitor, the controller has a
Slide 27: Current-Mode LLC with Frequency Control
Current-Mode LLC with Frequency Control Based on first-harmonic approximation (FHA), the DC gain can be controlled by adjusting the switching frequency Due to its limited DC gain range, the LLC converter does not easily accommodate large input and output voltage variations: • Fits well with the PFC
Slide 28: Agenda
Agenda ▪ Understanding Power Factor Correction ▪ MPS Solutions for PFCs ▪ Understanding Resonant Power Conversion ▪ MPS Solutions for LLCs ▪ Q&A
Slide 29: MPS LLC Controllers Roadmap
MPS LLC Controllers Roadmap HR1280 PFC + LLC Combo Full Digital PFC + LLC HR1210/1/3/5 Current-Mode LLC Full Digital PFC + LLC Current-Mode LLC HR1275 Full Digital PFC + LLC Current-Mode LLC HR1001A HR1001C HR1002/A HRxxxx Direct Freq. Control, Direct Freq. Control Direct Freq. Control Digital High
Slide 30: HR1001C Key Features
HR1001C Key Features • Adaptive Dead-Time Adjustment (ADTA) • Over-Current Protection (OCP) with Configurable Delay Time for Enhanced Surge Performance • Capacitive Mode Protection (CMP) • 50% Duty Cycle, Variable Frequency Control for Resonant Half- Bridge Converter • 600V High-Side Gate Driver wit
Slide 31: HR1001C Adaptive Dead Time
HR1001C Adaptive Dead Time Q1 Q2 ir ADTA Block Diagram im • Low Efficiency • Thermal Problems VSW • Higher Cost Soft switching at normal fSW increases Q1 Q2 at light loads ir im Adaptive dead time adjustment automatically LM Tolerance ensures ZVS even under light-load conditions VSW → High efficienc
Slide 32: HR1275 LLC Key Features
HR1275 LLC Key Features General System Features FBP 1 20 SO • Total <85mW No-Load Power Loss ACIN 2 19 CR CSP FBL • HV Current Source for Start-Up 3 18 PGND 4 17 UART/PG • Smart X-Capacitor Discharge during AC Dropout, Approved by IEC GATEP 5 HR1280 16 CSHB 62368 and IEC 60950 VREG 6 15 PG • Power G
Slide 33: HR1275 LLC Light-Load Burst Mode
HR1275 LLC Light-Load Burst Mode • Configurable Fixed VCOMP fBURST VB_ON • Configurable tH1 and tL1 FB Burst-on Burst-off tB-on tB-off • Configurable Skip Frequency HG • PWM On/Off Based on the FBL Voltage: tHG-ini Burst-On/Off Level LG • Burst Frequency Control • FBL Pull-Up Resistor Control for Po
Slide 34: HR12xx Start-Up Strategy
HR12xx Start-Up Strategy - During start-up, there is an imbalance in the resonant capacitor voltage, which can induce hard switching - To avoid hard switching, the LSG driver does not turn off until the resonant tank current drops below Start-Up: zero (VCSHB < VCSNR) - The low-side gate (LSG) turns
Slide 35: HR1275 LLC Waveforms
HR1275 LLC Waveforms Test Conditions: VIN = 220VAC, IOUT = 20A Test Conditions: VIN = 220VAC, IOUT = 10A High Load CH1: SW CH2: VCR CH3: FBL Test Conditions: VIN = 220VAC, IOUT = 2A Test Conditions: VIN = 220VAC, IOUT = 1A CH4: IR Burst Light Load
Slide 36: MPS LLC Design Tool
MPS LLC Design Tool Tutorial Specifications https://www.monolithicpower.com/en/design-tools/design-tools/llc-design-tool.html
Slide 37: MPS LLC SR Controllers Roadmap
MPS LLC SR Controllers Roadmap Dual Synchronous Rectification (SR) Controllers for LLC MP6925/A MP6926 MP6928A High-Frequency Fast Turn-Off, Intelligent High-Efficiency Dual SR LLC SR Dual SR • LLC SR Driver Target to high power density PD markets MP6922A MP6923 30mV VDS 15mV VDS Dual SR Dual SR MP6
Slide 38: MP6928A Key Features
MP6928A Key Features • Works with 12V Standard and 5V Logic-Level FETS • Fast Turn-Off Total Delay • 4.3V to 35V Wide VDD Operating Range • Tolerant to 200V Drain-to-Source Voltage • < 50μA uiescent urrent ( Q) • Supports High-Side and Low-Side Rectification
Slide 39: MP6928A Adaptive Forward Voltage
MP6928A Adaptive Forward Voltage • Fast Turn-Off Speed (About 35ns) • Supports CCM, DCM, and BCM Modes • Light-Load Function to Latch Off the Gate Driver under Light-load Conditions, Limiting the Current to 85μA • Drives two N-channel MOSFETs, Adaptive Forward Voltage Drop Regulation
Slide 40: HR1211 Reference Design Examples
HR1211 Reference Design Examples 600W Battery Charger USB PD 3.1 240W Parameter Specifications Input Voltage Parameter Specifications 85VAC to 265VAC Range Input Voltage Output Voltage 100VAC to 265VAC 35VDC to 58.8VDC (±1.5%) Range Range Output Voltage Output Current 10A (±1.5%) 3.3VDC to 48VDC Ran
Slide 41: Agenda
Agenda ▪ Understanding Power Factor Correction ▪ MPS Solutions for PFCs ▪ Understanding Resonant Power Conversion ▪ MPS Solutions for LLCs ▪ Q&A
Slide 42: Thank you!
Thank you! monolithicpower.com
Monolithic Power Systems — Technical Presentation (October 2023) on 6ix