FA1A60N/FA6B20N Reference Design - Power supply design example - 180W

Oct 12, 2026

Upload by Stanley

Reference design for an LLC converter power supply using PFC control IC FA1A60N and LLC IC FA6B20N, targeting 180W output with universal input (90Vac to 264Vac). Reliability is improved through capacitive mode prevention, high-accuracy overload and adjustable-delay overcurrent protection, and optimized PFC operation. Low standby operation reduces standby power via burst-mode behavior and optional auto/external-signal standby selection, with integrated protections (OCP/OVP, overheat, brown-in/out, UVLO) and efficiency targets at both typical and light loads.

LanguageEnglish

CategoryTechnology

FormatPDF

Pages12

Reading Time30 min

AccessFree to download

Overview

Features

Application circuit

Specifications of the power supply

Characteristics

Characteristics curves

Efficiency

Input power of light load

Cross regulation

PFC control IC FA1A60N LLC current resonant control IC FA6B20N Power supply design example： 180W Reference Design 1．Overview This document describes the design example of LLC converter using PFC IC FA1A60N and LLC IC FA6B20N.The input is universal (90Vac to 264Vac) and the output is 180W. To ensure high reliability of the power supply, the capacitive mode prevention function, high-accuracy overload protection function andovercurrent protection function with adjustable delay time are provided. In addition, efficiency at light load is improved with low standby mode, therefore auxiliary power supply for standby can be removed. Auto standby operation and Standby operation by external signal are selectable by mode selection function. When it is used with Fuji CRM PFC control IC “FA1A60N”, FA6B20N controls PFC IC operating mode (continuous, burst or stop operation) . It helps to improve efficiency of PSU, optimize the PFC operation and reduce external components. 2．Features 􀂋 FA6B20N 􀂄 The integrated startup circuit achieves downsized power supply and lower power consumption. 􀂄 Operating mode can be switched between normal operation mode and low standby mode. 􀂄 ”Auto standby operation” and “Standby operation by external signal” are selectable. 􀂄 During the low standby mode, standby power is lowered by the burst mode operation. 􀂄 Integrated input filter X-capacitor discharge function decreases loss due to discharge resistance. 􀂄 Low consumption current, 0 .80mA (Vcc quiescent current) . 􀂄 Integrated high-side and low-side drive circuits, which can be directly connected to the power MOSFET and operates with 50% duty cycle. 􀂄 Various protection functions: overcurrent (IS pin), overload (CA,FB pin),overvoltage (VCC pin), overheat and protection by external signal (MODE pin) . 􀂄 Integrated level-fixed brown-in/out function (VH pin) 􀂄 Various mode selection settings can be made: overcurrent protection (detection by IS pin) delay time setting, operation setting in standby mode, and adjusting output power switching to standby mode. 􀂄 Under voltage lock out function (VCC,VB pin) 􀂄 Package: SOP-16 (compliant with JEDEC) 􀂋 FA1A60N 􀂄 Operating mode can be switched between burst mode and normal mode by communication signal from“FA6B20N”. It helps to improve light load efficiency. 􀂄 Combining with “FA6B20N”, operation is optimized according to line voltage and distortion of line current is improved for wide input voltage range. 􀂄 Low standby power due to no input voltage detection resistors 􀂄 High-precision over current protection: 0 .6V±2% 􀂄 Improved power efficiency at light load by frequency reduction 􀂄 Reduced audio noise at start up by overshoot reduction and dynamic OVP 􀂄 Low current consumption by CMOS process, 􀂄 Start-up: 250µA(typ.), Operating: 0 .8mA(typ. ) 􀂄 Drive circuit for power MOSFET, peak current: source 500mA, sink 1000mA 􀂄 Protects the output electrolytic capacitor by the double OVP function, even if a fault happen in the output detection. 􀂄 Short protection at feedback (FB) pin 􀂄 Under-voltage Lockout 􀂄 Restart timer 􀂄 8-pin package (SOP) Mar,2019 RD_FA1A60N/FA6B20N_ 180W_E Rev1 .0 1 /12 © Fuji Electric Co., Ltd. All rights reserved. 3． Application circuit 4．Specifications of the power supply | Item | | Value | Unit | | --- | --- | --- | --- | | Input voltage | | 90 to 264 | Vac | | Output1 | Voltage | 12 | Vdc | | | Current | 5 | A | | Output2 | Voltage | 150 | Vdc | | | Current | 0.8 | A | 5．Characteristics | Item | | 110Vac | 230Vac | | --- | --- | --- | --- | | Efficiency | Typ Load(180W) | 89.7% | 92.0% | | | Light Load(5W) | 79.5% | 81.9% | | Input power | Po=120mW | 257mW | 249mW | | OLP | | 275W | | Mar,2019 RD_FA1A60N/FA6B20N_ 180W_E Rev1 .0 2 /12 © Fuji Electric Co., Ltd. All rights reserved. FA1A60N/FA6B20N Reference Design 6．Characteristics curves 􀂋 EFFICIENCY | Efficiency vs. Output power | | | | --- | --- | --- | |

FAQs

What input voltage range and output power does this 180W reference design support?

It supports a universal input range of 90Vac to 264Vac and targets a total output power of 180W.

Which ICs are used for PFC and LLC control in this design?

The design uses PFC control IC FA1A60N together with LLC control IC FA6B20N.

How does the design reduce standby power and select standby operation modes?

Low standby mode lowers standby power by using burst-mode operation, and standby behavior can be selected as auto standby or standby controlled by an external MODE signal.

Oct 12, 2026

Upload by Stanley