IRIR1155300W Energy Star Power Supply Reference Design

IR’s IR1155 is a micro-PFC device using IR’s proprietary “One-Cycle Control” (OCC) technology, using continuous conduction mode, programmable switching frequency 48kHz-200kHz, input voltage 85-264VAC, meet Energy Star, green energy and Blue Angel and other power standards. This article introduces the main features of IR1155, block diagram, application diagram and IRAC1155-300W reference design key specifications, circuit diagram and bill of materials.

The μPFC IR1155 power factor correction IC, based on IR proprietary “One Cycle Control” (OCC) technique, provides for high PF, low THD and excellent DC Bus regulation while enabling drastic reduction in component count, PCB area and design time as compared to traditional solutions. The IC is designed to operate in continuous conduction mode Boost PFC converters with average current mode control over 85-264VAC input line voltage range. Switching frequency can be programmed to anywhere between 48kHz to 200kHz based on the specific application requirement.

In addition, IR1155 offers several advanced system-enabling and protective features such as dedicated pin for over voltage protection, cycle by cycle peak current limitation, open loop protection, VCC UVLO, soft-start and micropower startup/sleep-mode with IC current consumption less than 200μA. The sleep mode, invoked by pulling the OVP/EN pin low, enables compliance with standby power requirements mandated by regulations such as Energy Star, Green Power, Blue Angel etc.

IR1155 main features:

• PFC IC with IR proprietary “One Cycle Control”

• Continuous conduction mode boost type PFC

• Programmable switching frequency (48k-200kHz)

• Average current mode control

• Output overvoltage protection

• Open loop protection

• Cycle by cycle peak current limit

• VCC under voltage lockout

• Programmable soft start

• Micropower startup

• User initiated micropower “Sleep Mode”

• OVP/EN pin internal filtering for higher noise immunity

• 1.5A peak gate drive

• Latch immunity and ESD protection

figure 1. IR1155 block diagram

figure 2. IR1155 application diagram

IRAC1155-300W Reference Design

IRAC1155-300W is a full function AC-DC reference design showcasing the operation of IR1155 PFC IC in a continuous conduction mode boost converter for achieving power factor correction, sub-10% harmonic current distortion and EN61000-3-2 Class D harmonic current limits standard compliance. Designed to be operated from 85-264VAC universal input voltage, IRAC1155-300W delivers 300W continuous output power via a fully regulated 388V DC bus. Thanks to IR1155 PFC IC, the reference design is rendered with a very high level of safety against system abnormalities such as DC bus voltage loop feedback loss, system overcurrent & overvoltage protection.

The IRAC1155-300W reference design is an excellent design example that can be seamlessly imported & integrated by system designers that require a high-performance PFC stage at the AC-DC front-end of their designs in a variety of applications.

Key features of the IRAC1155-300W reference design:

IEC61000-3-2 Class D Standards Compliant

Less than 10% Total Harmonic Distortion (115-230VAC/300W)

Power Factor higher than 0.99 (115-230VAC/300W)

Universal AC Input Voltage capability

Fully regulated 388V DC bus

Full load start-up, no minimum load requirements

Current loop controlled soft-current limit protection for overpower limitation at minimum VAC

Cycle-by-Cycle Peak Current Limit

Output Over Voltage Protection

Open Feedback Loop Protection

100kHz Switching Frequency

The main specifications of the IRAC1155-300W reference design:

image 3. IRAC1155-300W Reference Design Outline Drawing

Figure 4. IRAC1155-300W Reference Design Circuit Diagram
IRAC1155-300W Reference Design Bill of Materials: