Monolithic Power Systems´ (MPS) AC/DC Solutions

MPX2002

All-in-One Flyback Controller with Integrated Primary-Side Control Circuitry and Secondary-Side Synchronous Rectification Driver

The MPX2002 is an all-in-one flyback controller with an integrated primary driving circuit, secondary controller, synchronous rectification driver, and safety compliance feedback. The device provides the benefits of both primary-side regulation (PSR) and secondary-side regulation (SSR).

Without the need for a feedback circuit, the system is simplified, and the total BOM cost is reduced. The synchronous rectifier (SR) can match the driving signal of the primary-side MOSFET, which allows the SR to safely operate in continuous conduction mode (CCM). The integrated SR controller regulates the SR MOSFET at a low threshold to increase overall efficiency while providing a more flexible design.

An integrated, internal linear regulator provides the SR power supply, so the MPX2002 can drive the low-side SR MOSFET without auxiliary winding, even when the output is insufficient.

The MPX2002 can run in CCM under heavy loads, then switch to Quasi-Resonant (QR) operation when the load decreases. If the load drops further, the MPX2002 works in pulse-frequency modulation (PFM) mode. The switching frequency is fixed at 20kHz when it enters burst mode, which reduces audible noise. With this feature, the MPX2002 can achieve high efficiency under all load conditions with excellent electromagnetic interference (EMI) performance. The MPX2002 features advanced protections, including VCC over-voltage protection (OVP), primary over-current protection (POCP), secondary-sense output overload protection (OLP), internal brown-in (B/I) and brownout (B/O), short-circuit protection (SCP), current-sense short protection (SSP), SR gate open/short protection (SGOP/SGSP), SRD abnormal protection (SRDP), FB OVP and under-voltage protection (UVP), internal thermal shutdown, under-voltage lockout (UVLO), and an externally triggered protection (Ext.P). The MPX2002 is available in SOICW-16 and SOICW-16-T packages.

Download Datasheet

Features & benefits

• Isolation Voltage >4500VAC
• 100% Production HIPOT Compliance Testing
• UL1577 (Approved) and IEC62368 Safety Approved (Pending)
• Integrated Multi-Mode DCM/QuasiResonant (QR)/CCM Flyback Controller, Secondary-Side Synchronous Rectifier (SR) Sensing/Driving Circuitry, and a Safety Compliance Feedback Link
• Integrated 650V Primary-Side Current Source and 150V Secondary-Side Current Source
• Consumes Less than 30mW in Standby Mode
• Improved SR Control for Reliable Operation and Higher Efficiency
• VCC OVP, POCP, OLP, Internal B/O and B/I, SCP, Current-Sense Short Protection, SR Gate Open/Short Protection, SRDP, FB OVP/UVP, Internal Thermal Shutdown, UVLO, and Ext.P
• Available in Thin SOICW-16-T and Standard SOICW-16 Packages

Read more

• Article: Controlling Primary-Side Ringing
• Article: How Integration Is Advancing Innovations in Power Management

Related video

MPX2002: All-in-One Flyback Controller with Integrated Primary-Side and Secondary-Side Control

MP6908A

Fast Turn-Off Intelligent Rectifier with No Need for Auxiliary Winding

The MP6908 is a low-drop diode emulator IC that, when combined with an external switch, replaces Schottky diodes in high-efficiency flyback converters. The MP6908 regulates the forward drop of an external synchronous rectifier (SR) MOSFET to about 40mV, which switches off once the voltage becomes negative.

The MP6908 can generate its own supply voltage for battery charging applications with potential low output voltage, and at short circuit output condition, or for high-side SR configuration. Programmable ringing detection circuitry prevents the MP6908 from turning on falsely at Vds oscillations during discontinuous conduction mode (DCM) and quasi-resonant operation.

The MP6908 is available in a space-saving TSOT23-6 package.

Download Datasheet

Features & benefits

• Wide Output Range down to 0V, No Short Circuit Current Flows through Body Diode 
• No Need for Auxiliary Winding for High-Side or Low-Side Rectification
• Ringing Detection Prevents False Turn-On during DCM and Quasi-Resonant Operations
• Works with Standard and Logic Level SR MOSFETS
• Compatible with Energy Star
• ~30ns Fast Turn-Off and Turn-On Delay
• ~100µA Quiescent Current 
• Supports DCM, CCM, and Quasi-Resonant Operations
• Supports both High-Side and Low-Side Rectification
• TSOT23-6 Package Available

Read more

• Article: Designing a Synchronous Rectification Solution to Reduce Excessive Heat

HR1211

Multi-Mode PFC and Current Mode LLC Controller With Programmable Audible Noise Reduction Control

The HR1211 is a multi-mode PFC and current mode LLC combo controller that is configurable via UART interface. Power-saving technology helps achieve optimized efficiency across the full operating range.

The PFC controller employs a patented, digital average current control scheme to achieve hybrid CCM/DCM operation. Under heavy loads, CCM reduces the peak MOSFET current so the controller can be used across a wider load range. Under light loads, DCM reduces the switching frequency for better efficiency. Burst mode has configurable, digital soft switching to improve both light-load efficiency and audible noise.

Current mode control is implemented in the LLC stage to achieve good stability and fast response. Three operation modes are implemented based on the different load conditions: steady state, skip, and burst mode. This allows different load conditions to be independently optimized for efficiency. At light loads, digital, frequency-controlled burst mode is applied to reduce both switching power loss and audible noise. Adaptive dead-time adjustment (ADTA) and capacitive mode protection (CMP) is also applied to guarantee zero-voltage switching (ZVS) without capacitive mode operation.

The HR1211 has an internal, high-voltage current source for start-up, meaning that a traditional start-up resistor or external circuit is not required. The high-voltage (HV) current source can be implemented as an X-capacitor discharger when the AC input is in dropout, so a capacitor resistor is not required.

Protections include thermal shutdown (TSD), PFC open-loop protection (OLP), over-voltage protection (OVP), over-current limit (OCL) and LLC over-current protection (OCP), SO pin protection, and over-power protection (OPP).

The HR1211 is available in SOIC-20 and TSSOP-20 packages.

Advantages include: 

• CCM/DCM multi-mode PFC control with high efficiency (light-load efficiency ƞ > 80%)
• <100mW no-load power loss
• High power factor due to capacitor current compensation (>0.95 at 20% loads)
• UART interface and GUI to configure parameters

Download Datasheet

Features & benefits

• Operates at Frequencies Up to 500kHz in Steady State
• Smart X-Capacitor Discharges during AC Dropout, Approved by IEC62368 and IEC60950
• Built-In, High-Voltage Start-Up and X-Capacitor Discharger
• Digital Control for Both PFC and LLC
• Current Mode Control for LLC
• Improved Skip Mode Control for LLC for Low Audible Noise
• Adaptive Dead Time Adjustment (ADTA) for LLC
• Capacitive Mode Protection for LLC
• Configurable Soft Start
• Comprehensive Protections: Brown-In/Brownout, Over-Voltage Protection (OVP), Over-Current Protection (OCP), Open-Loop Protection (OLP)

Read more

• Article: Digital PFC + LLC Combo Controller Helps Fast-Charge Adapters Enter the New Age
• Article: Developing a Multi-Port Fast-Charge Solution with the HR1211
• Reference design: EVHR1211-Y-00B - 600W, Offline Battery Charger PFC + LLC with the HR1211 Evaluation Board

Related video

Multi-Mode PFC and Current Mode LLC 2-in-1 Controller: HR1211

MP6925

Fast Turn-Off, CCM/DCM Compatible, Dual-LLC Synchronous Rectifier with lmproved Noise Immunity

The MP6925 is a dual, fast turn-off, intelligent rectifier for synchronous rectification in LLC resonant converters.

The IC drives two N-channel MOSFETs, regulates their forward voltage drop to V_fwd (about 29mV), and turns the MOSFETs off before the switching current goes negative.

The MP6925 has a light-load function to latch off the gate driver under light-load conditions, limiting the current to 175μA.

The MP6925’s fast turn-off enables both continuous conduction mode (CCM) and discontinuous conduction mode (DCM).

The MP6925 requires a minimal number of external components, and is available in an SOIC-8 package.

Advantages include:

• Fast turn-off speed
• Has light-load function
• Drives two N-channel MOSFETs
• Regulates forward voltage drop to about 29mV
• Supports CCM, DCM, and CrCM mode

Download Datasheet

Features & benefits

• Wide 4.2V to 35V VDD Operating Range
• 175μA Low Quiescent Current in Light-Load Mode
• Supports High-Side and Low-Side Rectification
• Compatible with Energy Star
• Requires a minimal number of external components

Read more

• Reference design: EV6925-S-00A - High Efficiency Synchronous Rectification EV Board

HF920

900V, Fixed-Frequency, Offline Regulator w/ Ultra-Low Standby Power Consumption

The HF920 is a flyback regulator with a monolithic, 900V MOSFET. The HF920 provides excellent power regulation in AC/DC applications that require high reliability, such as smart meters, large appliances, industrial controls, and products powered by poor AC grids. The HF920 requires a minimal number of external components.

The HF920 uses peak-current-mode control to provide excellent transient response and easy loop compensation. When the output power falls below a given level, the regulator enters burst mode. The IC consumption is also specially optimized. As a result, the HF920 achieves very low power consumption during standby conditions.

MPS’s proprietary, 900V, monolithic process enables an over-temperature protection (OTP) that is on the same silicon as the 900V power MOSFET, offering the most precise thermal protection. The HF920 also offers a full suite of protection features such as VCC under-voltage lockout (UVLO), overload protection (OLP), over-voltage protection (OVP), and short-circuit protection (SCP).

The HF920 is designed to minimize electromagnetic interference for power line communications (PLC) in home and building automation applications. The operating frequency is programmed externally with a single resistor, so the power supply’s radiated energy can be designed to block interference to the PLC. In addition to the programmable frequency, the HF920 employs frequency jittering that reduces the noise level and EMI filter cost greatly.

Frequency-doubling mode operation can be enabled through a simple external set-up. With this special operation mode, the switching frequency is doubled when the converter runs into an over-power condition. In this way, the converter is able to handle up to a 50% decrease of the transformer inductance caused by external magnetizing interference.

Download Datasheet

Features & benefits

• Monolithic 900V/15Ω MOSFET and High-Voltage Current Source
• Fixed Switching Frequency, Programmable up to 150kHz
• Current-Mode Control Scheme
• Frequency Jittering
• Low Standby Power Consumption via Active Burst Mode
• <30mW No-Load Consumption
• Frequency Doubling Operation Mode
• Internal Leading-Edge Blanking (LEB)
• Built-In Soft-Start (SS) Function
• Internal Slope Compensation
• External Input PRO Pin Protection with Hysteresis and Auto-Restart Recovery
• Over-Temperature Protection (OTP)
• VCC Under-Voltage Lockout (UVLO) with Hysteresis
• Over-Voltage Protection (OVP) on VCC
• Time-Based Overload Protection (OLP)
• Short-Circuit Protection (SCP)
• Available in SOIC8-7A and SOIC14-11 Packages

Read more

• Article: Voltage Regulator Types and Working Principle
• Reference design: EVHF920-S-00B - 85VAC/60Hz~350VAC/50Hz 16.5V/300mA;16.5V/100mA Off-line Switching Regulator