High-Voltage Power Supply Controller Family

Power Integrations'  InnoSwitch™ Family of ICs has been introduced at Electronica 2014, it combines primary, secondary and feedback circuits in a single surface-mounted off-line flyback switcher IC. The IC incorporates the primary FET, the primary-side controller, a secondary-side controller for synchronous rectification and an innovative FluxLink™ technology that eliminates the need for an optocoupler. Now that IC family has been extended to support higher voltage applications.

The new InnoSwitch TM-EP family of ICs simplify the development and manufacturing of low-voltage, high-current power supplies, particularly those in compact enclosures or with high efficiency requirements. Its architecture is revolutionary in that the devices incorporate both primary and secondary controllers, with sense elements and a safety-rated feedback mechanism into a single IC.

Close component proximity and use of the integrated communication link permit accurate control of a secondary-side synchronous rectification MOSFET and optimization of primary-side switching to maintain high efficiency across the entire load range. Additionally, the minimal DC bias requirements of the link, enable the system to achieve less than 10 mW no-load to maximize efficiency in standby.

The InnoSwitch-EP combines a high-voltage (725 V) power MOSFET switch, along with both primary-side and secondary-side controllers in one device. It has a novel inductive coupling feedback scheme using the package leadframe and bond wires to provide a reliable and low-cost means to provide accurate direct sensing of the output voltage and output current on the secondary to communicate information to the primary IC. Unlike conventional PWM (pulse width modulated) controllers, it uses a simple ON/OFF control to regulate the output voltage and current. The primary controller consists of an oscillator, a receiver circuit magnetically coupled to the secondary controller, current limit state machine, 5.95 V regulator, over-voltage circuit, current limit selection circuitry, over-temperature protection, leading edge blanking and the power MOSFET. The secondary controller consists of a transmitter circuit that is magnetically coupled to the primary receiver, constant voltage (CV) and constant current (CC) control circuitry, a 4.4 V regulator, synchronous rectifier MOSFET driver, frequency jitter oscillator and a host of integrated protection features.

More in our upcoming printed issue!

Samples are available now. Devices are priced at $1.08 in 10,000-piece quantities. A reference design, RDK-469, is also available.