PCIM Asia Papers Focus on Powering White Goods, 3-D Televisions, and Consumer ElectronicsJune 21, 2012 by Jeff Shepard
Technical papers at this year’s PCIM Asia event in Shanghai focused on a wide variety of topics including powering white goods, power for 3-D televisions and high-voltage power management ICs suitable for powering consumer devices up to 100W. Presenters of these papers represented LS Power Semitech Co. Ltd. of Korea, Fairchild Semiconductor China and Fuji Electric Co, Ltd., respectively.
During the poster session, a team from LS Power Semitech discussed a new CIPOS (Control Integrated Power System) in a transfer-molded DIL (Dual-in-line) package. Targeted at white goods applications such as refrigerators, the device combines six fast reverse recovery MOSFETs in a three-phase inverter structure and a custom SOI (Silicon On Insulator) gate driver.
According to the authors, most intelligent power modules (IPMs) use a highly thermally conductive interface material to connect the power transistors to the heat sink. This can be expensive and requires a complex assembly technology. In the new 500V/10A CIPOS the power components are isolated from the heat sink and all the low-power components are assembled on a separate, internal, PCB. The lead frame style package is produced using a low-cost module assembly process and the resulting DIL structure can be soldered directly into the drive board like any other through-hole integrated circuit.
Also during the poster session, a team from Fairchild Semiconductor China presented the powering needs of the latest-generation of 3-D televisions. 3-D TV requires 2-3 times peak power in 3-D operation compared with 2-D operation, but average power is almost the same in both modes.
Usually there are three primary power outputs of the main power supply in LED TVs: standby, signal processing and backlight. The power requirement of standby and signal processing is very similar in both 2-D and 3-D televisions. Dimming in 2-D TVs is straight forward and simple to design. In the case of 3-D TVs, the design of the backlighting power system is more complex. There are two primary types of 3-D TVs currently being produced. One 3-D technology uses polarization glasses while the other type relies on shutter glasses. Polarization designs currently have the lowest market share and are the simplest to design. The more popular polarization TVs depend on complex dimming capabilities.
Polarization type 3-D does not need backlight sequence coordination, so the power requirement is no different between 2-D mode and 3-D mode. 3-D TVs employing shutter classes require backlit sequence coordination. In shutter 3-D mode the backlight only operates in two states: ON and OFF. Shutter 3-D technology is used with active shutter glasses. One frame only shows one eye’s image. The screen alternately displays the left and right images, and at the same time system synchronizes 3-D glasses through an infrared control signal from the TV set to the glasses. The shutters in the glasses are used to control the 3-D effect. To reduce the screen flashing and ghosting issues the system needs a higher frame rate and must match with the coordinated control of the backlight.
On the last morning of presentations, a team from Fuji Electric discussed a new 600V-class power management IC (PMIC) delivering up to 91.5% with an output power of 100W and a 230Vac input. Called the FA5760, the new device is designed for use in LLC current resonant type converters. It includes a 600V Junction FET (J-FET) and high-side triple well devices, and 30V- and 5V- CMOS circuits on a single chip the device integrates high-side and low-side drive circuits, a level-shift circuit, a start-up circuit and a PWM control circuit. Using the FA5760, it is possible to design a wide-input (85Vac-264Vac) ac-dc converter with 103 components (including PFC), compared with a conventional design that requires 159 components.
The FA5760 is fabricated using Fuji’s 800V HVIC technology. The main features of this IC include a built-in 600V start-up J-FET, internal 600V high-side drive circuit, very low standby power (80mW) under no loads at input ac voltage of 100V, and built-in protection functions for over current, over load, and over voltage.