Switcher ICs Integrate 900V MOSFETs for Isolated Flybacks & Non-Isolated BucksMay 08, 2019 by Scott McMahan
Power Integrations announced the release of a suite of offline switcher ICs incorporating 900V primary MOSFETs. The newly-released devices include ICs for high-efficiency isolated flyback power supplies and for simple non-isolated buck converters.
Applications include three-phase industrial power supplies up to 480Vac, and high-quality consumer products for regions with unstable mains grids. Additionally, the offline switcher ICs can be used in tropical regions with frequent lightning strikes, or any area where high-energy ring-waves and surges are prevalent. Other typical applications include appliances, metering, smart LED drivers and industrial controls, as well as IoT, home, and building automation.
The new products include 900V versions of the LinkSwitch™-TN2 ICs for simple, non-isolated buck converters plus three new members of the flagship InnoSwitch™3-EP IC family. The InnoSwitch™3-EP IC family enables extremely high-efficiency isolated flybacks up to 35W.
All members of the 900V product families feature internal control engines optimized for high efficiency across the load, allowing designs to readily meet energy-related products (ErP) limits. A variety of line and load protection mechanisms further enhance system robustness and reliability.
According to Power Integrations, the 900V LinkSwitch-TN2 ICs deliver the lowest-component-count switcher solutions for buck converters. They feature fully integrated auto-restart for short-circuit and open-loop protection as well as a selectable current limit.
The use of frequency jittering significantly reduces EMI, and the company says that the devices easily meet high-voltage creepage and clearance requirements between DRAIN and all other pins both on the PCB and at the package.
The 900V LinkSwitch-TN2 allows the use of low-cost off-the-shelf inductors, and it reduces the size and cost of magnetics and output capacitor.
The 900V InnoSwitch3-EP flyback switcher ICs deliver lossless line OVP sensing that automatically interrupts switching when line voltages exceed a selected threshold, preventing damage to the power supply during severe line overvoltage scenarios. The devices achieve efficiencies of up to 90% across line and load conditions, reducing power supply losses and resulting in compact power supplies up to 35W without heatsinks.
Typical buck converter application
The enhanced safety and reliability features include auto-restart for short-circuit and open loop faults, output over-voltage protection (OVP), line input over-voltage protection (OVL), and hysteretic over-temperature protection (OTP).
900V InnoSwitch3-EP ICs
The 900V InnoSwitch3-EP ICs employ Power Integrations' isolated digital communications technology, FluxLink™, plus synchronous rectification (SR), QR switching and a precise secondary-side feedback sensing, and control circuit. The company says that this technology results in highly efficient, accurate, reliable power supply circuits without the need for unreliable optocouplers.
Typical application schematic
The 900V InnoSwitch3-EP ICs have advanced protection and safety features including open SR FET-gate detection, fast input line UV/OV protection, and auto-restart fault response for output OVP. The device has auto-restart output UV protection with an option for peak power delivery.
"These switching power ICs enable designers of three-phase utility meters, motors, industrial auxiliary power supplies, appliances and even cellphone chargers to realize a truly ‘one-world' power supply that meets the reliability expectations of users everywhere. For example, OEMs addressing the burgeoning market in India for high-quality consumer products suffer a continuous stream of electrically damaged and returned products that must be serviced or replaced. Our 900V switcher ICs provide effective and inexpensive protection and a substantial reduction in operating and product-support costs," Senior Product Marketing Manager Silvestro Fimiani commented.
Product Highlights of LinkSwitch-TN2
Highest Performance and Design Flexibility
- Supports buck, buck-boost and flyback topologies
- Excellent load and line regulation
- Selectable device current limit
- 66kHz operation with accurate current limit
- Allows the use of low-cost off-the-shelf inductors
- Reduces size and cost of magnetics and output capacitor
- Frequency jittering reduces EMI filter complexity
- Pin-out simplifies PCB heat sinking
Enhanced Safety and Reliability Features
- Auto-restart for short-circuit and open loop faults
- Output overvoltage protection (OVP)
- Line input overvoltage protection (OVL)
- Hysteretic over-temperature protection (OTP)
- Extended creepage between DRAIN pin and all other pins improves field reliability
- 900V MOSFET rating series for industrial or extra safety margin
EcoSmart- Extremely Energy Efficient
- Standby supply current <100µA
- On/Off control provides constant efficiency over a wide load range
- Easily meets all global energy efficiency regulations
- No-load consumption <30mW with external bias
Product Highlights of 900V InnoSwitch3-EP ICs
- Highly Integrated, Compact Footprint
- Very high efficiency across full load range
- Incorporates a multi-mode Quasi-Resonant (QR) / CCM flyback controller,
- 900V MOSFET, secondary-side sensing and synchronous rectification driver
- Excellent multi-output cross regulation with weighted secondary-side regulation (SSR) feedback and synch FETs
- Integrated FluxLink, HIPOT-isolated, feedback link
- Exceptional CV/CC accuracy, independent of external components
- Adjustable accurate output current sense using external output sense resistor
EcoSmart - Energy Efficient
- Less than 15mW no-load including line sense
- Easily meets all global energy efficiency regulations
- Low heat dissipation
Advanced Protection / Safety Features
- Open SR FET-gate detection
- Fast input line UV/OV protection
- Auto-restart fault response for output OVP
- Auto-restart output UV protection with option for peak power delivery
Full Safety and Regulatory Compliance
- Reinforced isolation
- Isolation voltage >4000Vac
- 100% production HIPOT testing
- UL1577 and TUV (EN60950) safety approved
- Excellent noise immunity enables designs that achieve class "A" performance criteria for EN61000-4 suite; EN61000-4-2, 4-3 (30 V/m), 4-4, 4-5, 4-6, 4-8 (100 A/m) and 4-9 (1000 A/m) and Ford FMC1278 (RI-115)
- Halogen-free and RoHS compliant
Samples of the 900 V InnoSwitch3-EP ICs are now available, priced at $1.18 for 10,000-piece quantities. Samples of 900 V LinkSwitch-TN2 ICs are also available for $0.60 each in 10,000-pieces orders.