L6566B:Multi-mode controller for SMPS

The L6566B is an extremely versatile current-mode primary controller ICs, specifically designed for high-performance offline flyback converters. It is also suited for single-stage single-switch input-current-shaping converters (single-stage PFC) for applications supposed to comply with EN61000-3-2 or JEITA-MITI regulations.

Both fixed-frequency (FF) and quasi-resonant (QR) operation are supported. The user can pick either of the two depending on application needs. The device features an externally programmable oscillator: it defines converter’s switching frequency in FF mode and the maximum allowed switching frequency in QR mode.

When FF operation is selected, the ICs work like a standard current-mode controller with a maximum duty cycle limited at 70 % min. The oscillator frequency can be modulated to mitigate EMI emissions.

QR operation, when selected, occurs at heavy load and is achieved through a transformer demagnetization sensing input that triggers MOSFET’s turn-on. Under some conditions, ZVS (zero-voltage switching) can be achieved. Converter’s power capability rise with the mains voltage is compensated by line voltage feedforward. At medium and light load, as the QR operating frequency equals the oscillator frequency, a function (valley skipping) is activated to prevent further frequency rise and keep the operation as close to ZVS as possible.

With either FF or QR operation, at very light load the ICs enter a controlled burst-mode operation that, along with the built-in non-dissipative high-voltage start-up circuit and the low quiescent current, helps keep low the consumption from the mains and meet energy saving recommendations.

An innovative adaptive UVLO helps minimize the issues related to the fluctuations of the self-supply voltage due to transformer’s parasites.

The protection functions included in this device are: not-latched input undervoltage (brownout), output OVP (auto-restart or latch-mode selectable), a first-level OCP with delayed shutdown to protect the system during overload or short circuit conditions (autorestart or latch-mode selectable) and a second-level OCP that is invoked when the transformer saturates or the secondary diode fails short. A latched disable input allows easy implementation of OTP with an external NTC, while an internal thermal shutdown prevents IC overheating.

Programmable soft-start, leading-edge blanking on the current sense input for greater noise immunity, slope compensation (in FF mode only), and a shutdown function for externally controlled burst-mode operation or remote ON/OFF control complete the equipment of this device.

Key Features

  • Latched or autorestart OVP
  • Programmable frequency modulation for EMI reduction
  • -600/+800 mA totem pole gate driver with active pull-down during UVLO
  • Brownout protection
  • SO16N package
  • Pulse-by-pulse OCP, shutdown on overload (latched or autorestart)
  • Line feedforward for constant power capability vs. mains voltage
  • Selectable multi-mode operation: fixed frequency or quasi-resonant
  • Advanced light load management
  • On-board 700 V high-voltage start-up
  • Adaptive UVLO
  • Transformer saturation detection
  • Low quiescent current (< 3 mA)
Product Specifications
DescriptionVersionSize
DS5412: Multi-mode controller for SMPS3.1619 KB
Application Notes
DescriptionVersionSize
AN3089: 19 V - 65 W quasi-resonant flyback adapter using L6566B and TSM10142.0644 KB
AN4248: 60 W PSU design details for water purifier system1.03 MB
Presentations
DescriptionVersionSize
Primary side regulation controllers portfolio1 MB
Brochures
DescriptionVersionSize
Brochure Power management guide05.20164 MB
Solution Evaluation Tools
Part NumberManufacturerDescription
STEVAL-ISA161V1STEvaluation board for the SEA01 constant voltage and current controller with online digital trimming
Sample & Buy
Part NumberPackagePacking TypeUnit Price (US$) *QuantityECCN (EU)ECCN (US)Country of Origin
L6566BSO-16Tube--NECEAR99CHINA
L6566BTRSO-16Tape And Reel--NECEAR99CHINA
Quality & Reliability
Part NumberPackageGradeRoHS Compliance GradeMaterial Declaration**
L6566BSO-16IndustrialEcopack2md_q7-wspc-so16.15jedecms-012_baq7-wspc-mu63afx.pdf
md_q7-wspc-so16.xml
L6566BTRSO-16IndustrialEcopack2md_q7-wspc-so16.15jedecms-012_baq7-wspc-mu63afx.pdf
md_q7-wspc-so16.xml
Multi-mode controller for SMPS L6566B
circuit_diagram_13795_thumbnail.png L6566B
19 V - 65 W quasi-resonant flyback adapter using L6566B and TSM1014 EVL6566B-65W-QR
60 W PSU design details for water purifier system L6566B
48 V - 130 W high efficiency converter with PFC for LED street lighting applications - European version L6599AT
Very low drop voltage regulators with inhibit KFXX
md_q7-wspc-so16.15jedecms-012_baq7-wspc-mu63afx.pdf L6566B
md_q7-wspc-so16.xml L6566B