The µPFC family of controller ICs radically alters traditional thinking about PFC solutions. The IR115x uses a new, patented “One-Cycle Control, integrator with reset” technique to deliver the high performance of Continuous Conduction Mode (CCM) PFC with the simplicity and low component count of Discontinuous Current Mode (DCM).

OCC does not have the traditional analog multiplier, AC line sensing or fixed oscillator ramp. In OCC the output of the error amplifier is integrated over each clock cycle to generate a variable-slope ramp. This variable ramp is compared with the error voltage and subtracted from the current sense signal to generate the PWM gate drive.

High Power (>200W) Systems

High power applications (>200W) need CCM PFC to have high efficiency and small system sizes. However, traditional CCM multiplier-based solutions are complex, require many design stages and have a high component count, making CCM solutions very expensive.

In a typical 1kW SMPS, the new OCC solution has 40% fewer resistors and capacitors, and has a 50% smaller PCB area for the PFC control section. In addition, the IR115x has a dedicated Over Voltage Protection (OVP) pin to give greater protection for high power systems.

IR’s Ultrafast and Warp IGBTs can be used with these drivers for systems with power ratings higher than 750 Watt and switching frequency up to 100 kHz. In high power systems, IGBTs enable high efficient systems and can reduce system cost.

Low Power (<250W) Systems

Lower power applications (<250W) traditionally use DCM systems for simplicity and low system cost. However, as system power increases to 100W and above – e.g. for high end laptop or LCD TV adaptors - DCM systems are large due to high peak currents and EMI filter requirements. OCC operates in CCM mode with reduced peak currents and a 43% reduction in EMI filter needs. This translates into a 16% reduction in PCB and an increase in power density of 10% for a typical 120W laptop adaptor.

Governmental & Energy Standards Compliance

The IR115x includes features such as enable, micro-power start-up and “sleep mode” for compliance with energy efficiency standards such as “1W Standby”, Blue Angel and Energy Star.

DESIGN SUPPORT TOOLS:

PFC Design Software

Reference Designs

Application Notes

THE IR ADVANTAGE

	Small, easy, powerful solution
	Enables high power density
	Fast time to market
	Enables compliance with PFC (THD) regulations for Japan, Europe, and China
	Enables compliance with energy standards (1W, Blue Angel, Energy Star)
	No AC line voltage sense required
	0.999 power factor
	Switching frequency of 22kHz, 66kHz or programmable fixed value available
	Average current mode control
	Dedicated OVP with soft start, brownout and open loop protection
	Cycle by cycle peak current limit system protection
	For high power systems (>200W) - 40% fewer resistors and capacitors - 50% smaller PCB area for the PFC control section
	For lower power systems (<250W) - Reduced peak currents - 40% reduction in EMI filter cost - >16% smaller PCB - >10% higher power density

APPLICATIONS

	AC-DC smps >75W - Server SMPS & Telecom Rectifier - LCD TVs, mini-PC power adapters - Plasma TVs - LED street light - Home theatre systems - Office machines such as photocopiers and printers - PC silver box power supplies
	Motor Drive / Pumps >75W - Washing machines, dish washers - Air conditioners - Pools, spas, well pumps