LLC Resonant mode Controller

Resonant mode power supplies are a variation over SMPS circuits where the switching losses are significantly reduced by adapting zero-voltage or zero-current switching techniques, also known as soft-switching technique. Whereas non-resonant mode SMPS circuits, the switches are subjected to hard switching. Thus, resonant mode power supplies is much preferred to achieve higher efficiency. LLC HB Resonant operates under the ZVS mode, whereby switching loss is reduced so that the converter at higher switching frequency. And it can optimize the converter further at high input voltage. This topology allow us to eliminate the secondary filter inductor, adopt better rectifier diodes and secondary conduction loss is reduced. The converter utilizes leakage and magnetizing inductance of a transformer. With magnetic integration concept, all the magnetic components can be built in one magnetic core.

ICE1HS01G resonant mode converter, housed in a DSO-8 package, is an easy-to-design component to realise a LLC HB resonant application. An oscillator is built-in allowing designers to set the suitable operation frequency range with a resistor. In addition, ICE1HS01G offers a programmed soft-start function to limit both the inrush current and the overshoot in output voltage. To protect the system during operation, mains input under-voltage protection and over-current protection are also in-built. Hence, it is able to operate in resonant mode with the highest reliability possible.

ICE2HS01G is a high performance resonant mode controller designed especially for high efficiency half-bridge or full-bridge LLC resonant converter with synchronous rectification at the secondary side. With its new driving techniques, the synchronous rectification can be realized for LLC converter operated with secondary switching current in both CCM and DCM conditions. No special synchronous rectification controller IC is needed at the secondary side. The maximum switching frequency is supported up to 1MHz.

Except the patented SR driving techniques, this IC provides very flexible design and integrates full protection functions as well. It is adjustable for maximum/minimum switching frequency, soft-start time and frequency, dead time between primary switches, turn-on and turn-off delay for secondary SR MOSFETs. The integrated protections include input voltage brownout, primary three-levels over current, secondary over load protection and no-load regulation.