PWM-QR (quasi resonant) Flyback ICs

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Infineon latest 5 th generation quasi-resonant flyback PWM controller ICE5QSAG offers high performance and comprehensive suite of protection to increase system robustness. With a patent pending novel quasi-resonant implementation, an intelligent adaptive digital algorithm has enabled the PWM controller to minimize the spread of switching frequency under different AC line input conditions.
This innovative approach has enabled SMPS designers to design with higher switching frequency to take advantage of smaller magnetics and lowering of system BOM cost. To increase system robustness, both line input OVP and brown IN/OUT protection have been incorporated thereby reducing BOM count with high integration. To prevent controller damage due to abnormal start-up conditions, VCC and CS pin short to ground protection have been implemented to further enhanced system robustness.
To minimize interruption to system operation, all protection modes are implemented with auto-resume to enhance user experience. 5 th generation quasi-resonant PWM controller ICE5QSAG is targeted for SMPS applications such as auxiliary power supply for home appliances (e.g. washing machines, refrigerators and air-condition), set-top-box, LCD/LED monitor and general purpose power supply up to a maximum output power of 60W.
Comparison between 5Q and 2Q quasi-resonant flyback controller 

ICE5QSAG features

  • Novel quasi-resonant switching scheme
  • Rapid and adjustable start-up with cascode configuration
  • 2 level selectable active burst mode level
  • Built-in digital soft-start
  • Cycle by cycle peak current limitation
  • Digital frequency reduction with decreasing load for higher efficiency
  • Adjustable line input over-voltage and brown IN/OUT protection
  • VCC and CS pin short to ground protection
  • OLP, output short, output over-voltage, OTP with hysteresis and VCC over/under voltage protection
  • Auto-restart for all protection features

SMPS demoboard with ICE5QSAG

NEW! 5th generation quasi-resonant CoolSET™

Product Product Status Order Online Packages Green Applications Output Current Type VCC ICC
Matching Results: 4
descending ascending         descending ascending descending ascending descending ascending descending ascending descending ascending
Generation 5

active and preferred

Buy online


Off-line SMPS
- 10.5 V
24.0 V
Generation 2

active and preferred

Buy online


Off-Line SMPS
MOSFET Gate Driver
11.0 V
27.0 V
2.0 mA


Buy online


Off-Line SMPS
MOSFET Gate Driver
10.5 V
24.0 V
2.3 mA

not for new design




Off-Line SMPS
MOSFET Gate Driver
10.5 V
24.0 V
2.3 mA

Comparison between 5Q and 2Q quasi-resonant flyback controller

Switching Scheme Novel QR QR QR
Zero Crossing Counters 10 7 7
HV Start-up Cell Cascode Yes No
Active Burst Mode QR FF-52Khz N/A
Selectable Active Burst Mode Yes No N/A
Line Input OVP Auto-restart N/A N/A
Brown IN/OUT Auto-restart N/A Auto-restart
Output OVP Auto-restart Latch Latch
Short-winding N/A Latch Latch
VCC Undervoltage Auto-restart Auto-restart Latch
VCC pin Short to Ground Yes N/A N/A
CS pin Short to Ground Yes N/A N/A
Adjustable OLP Blanking Time No No Yes
Package PG-DSO-8 PG-DSO-8 PG-DSO-8


Product Selection Guide

Title Size Date Version
22.2 MB 21 Feb 2017 00_00

Application Notes

Title Size Date Version
3.6 MB 13 Dec 2016 01_00
3.4 MB 05 Apr 2017 01_00
2.6 MB 07 Sep 2016 02_00
2.8 MB 18 Mar 2015 01_00
1.2 MB 17 Mar 2017 01_00
312 KB 26 Jun 2008 01_00
2.6 MB 01 Mar 2016 01_00
1.5 MB 06 Mar 2017 01_00
2.4 MB 27 Nov 2014 01_01
960 KB 26 Jun 2008 01_00
1.1 MB 07 Apr 2010 01_00
2.4 MB 27 Nov 2014 01_01
905 KB 07 Apr 2010 01_00
2.2 MB 02 Jul 2014 01_00
2.6 MB 02 Jul 2014 01_00
1.6 MB 20 Feb 2014 01_01
1.3 MB 25 Jun 2008 01_00

Application Brochure

Title Size Date Version
879 KB 04 May 2016 01_00

Product Brief

Title Size Date Version
121 KB 13 Mar 2017 01_00

Evaluation Boards

Board Family Description Status
EVAL_45W_19V_FLYB_P7 MOSFET, Power Controller (PWM, PFC) 45W Adapter Demo Board
  • 2N7002
  • ICE2QS03G
  • IPA80R450P7
active and preferred
DEMO_5QSAG_50W1 MOSFET, Power Controller (PWM, PFC) 50W Dual Output +12V and +5V SMPS Quasi-Resonant demo board
  • IPA80R650CE
active and preferred
EVAL_15W_5V_FLYB_P7 This is a 15W 5.0V/3.0A USB adapter reference design using Quasiresonant PWM IC ICE2QS03G, CoolMOS™ IPS70R1K4P7S (IPAK), OptiMOS™ BSC067N06LS3G and high Speed Switching Diode BAS21-03W in a slim plug form factor with various mode of protections.
  • BAS21-03W
  • BSC067N06LS3G
  • ICE2QS03G
  • IPU70R1K4P7S
active and preferred
EVAL_40W_19V_FLYB_P7 MOSFET, Power Controller (PWM, PFC) Test platform for low cost charger and adapter applications
  • 2N7002
  • ICE2QS03G
  • IPA70R600P7S
active and preferred
REF-45W ADAPTER MOSFET, Power Controller (PWM, PFC) This reference board is intended to be a form, fit and function test platform for low cost and high power density applications
  • ICE2QS03G
  • IPA60R650CE
active and preferred

Reference Design

Title Size Date Version
8.1 MB 12 Nov 2011 01_02

PCB Design Data

Title Size Date Version
12 KB 22 Oct 2013 01_00
9 KB 22 Oct 2013 01_00
2 KB 22 Oct 2013 01_00
10 KB 22 Oct 2013 01_00

Simulation Tool

Title Size Date Version
783 B 27 Sep 2016 01_00

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Development Tools

Title Size Date Version
200 KB 22 Oct 2013 01_00
268 KB 10 Mar 2017 01_00