Infineon ICE2AS01G: A High-Performance Green-Mode PWM Controller for Offline SMPS

The relentless drive for energy efficiency and compact design in power electronics has made Switch-Mode Power Supplies (SMPS) the dominant solution for converting AC line voltage to regulated DC power. At the heart of a reliable and efficient offline SMPS is the pulse-width modulation (PWM) controller. The Infineon ICE2AS01G stands out as a premier integrated circuit designed specifically for this critical role, offering a blend of high performance, robust protection, and exceptional energy savings.

This controller is engineered for flyback converter topologies, which are ubiquitous in applications such as adapters for laptops and consumer electronics, auxiliary power supplies (AUX), and low-power LED drivers. Its primary function is to regulate the output voltage by precisely controlling the switching duty cycle of a power MOSFET, ensuring stable operation under varying load and input conditions.

A key feature of the ICE2AS01G is its green-mode operation. This proprietary technology significantly enhances light-load and no-load efficiency by reducing the controller's switching frequency. As the output power demand decreases, the IC intelligently lowers its operating frequency, thereby minimizing switching losses that are a major source of power consumption in standby mode. This makes end-products compliant with stringent international energy efficiency standards like Energy Star and EU CoC Tier 2.

Beyond efficiency, the ICE2AS01G is built for robustness and system safety. It incorporates a comprehensive suite of protection features that safeguard both the power supply and the connected load. These include:

Over-Current Protection (OCP): Monitors primary current to prevent transformer saturation and MOSFET overstress.

Over-Voltage Protection (OVP): Shields the system from dangerously high output voltages.

Over-Load Protection (OLP): Prevents sustained operation under excessive load conditions.

Brown-In/Out Protection: Ensures clean startup and shutdown during unstable AC line conditions.

Internal Soft-Start: Mitigates inrush current at startup, reducing stress on components.

The controller operates in a current-mode control scheme, which offers superior line voltage rejection and faster transient response compared to voltage-mode control. This results in a more stable output and simplifies the feedback loop compensation network. Furthermore, its fixed 65kHz switching frequency at full load provides an optimal balance between magnetic component size and switching noise, contributing to a compact and cost-effective design.

ICGOODFIND: The Infineon ICE2AS01G is a highly integrated, feature-rich PWM controller that exemplifies modern power supply design priorities. Its exceptional green-mode performance drastically cuts standby power consumption, while its comprehensive built-in protection features enhance system reliability and safety. For designers of offline flyback SMPS up to 100W, this IC represents a top-tier solution for creating compact, efficient, and robust power supplies that meet global energy regulations.

Keywords:

PWM Controller

Green-Mode Operation

Offline SMPS

Current-Mode Control

Flyback Converter