Overview
The L6566B is an extremely versatile current-mode primary controller IC, specifically designed for high-performance offline flyback converters and single-stage single-switch input-current-shaping converters. It is manufactured by STMicroelectronics and supports both fixed-frequency (FF) and quasi-resonant (QR) operation, allowing users to select the mode based on application needs. The IC features an externally programmable oscillator that defines the converter's switching frequency in FF mode and the maximum allowed switching frequency in QR mode. This controller is ideal for applications requiring high efficiency, advanced protection features, and low power consumption.
Key Specifications
| Parameter | Description |
|---|---|
| Package Style | SOIC-16N |
| Mounting Method | Surface Mount |
| Maximum Duty Cycle | 70% (min) in FF mode |
| Switching Frequency | Externally programmable |
| High-Voltage Start-Up | On-board 700 V |
| Quiescent Current | < 3 mA |
| Gate Driver Current | -600/+800 mA totem pole gate driver |
| Operating Temperature (°C) | -40 to 150 |
Key Features
- Selectable multi-mode operation: fixed frequency or quasi-resonant
- On-board 700 V high-voltage start-up
- Advanced light load management
- Low quiescent current (< 3 mA)
- Adaptive UVLO
- Line feedforward for constant power capability vs mains voltage
- Pulse-by-pulse OCP, shutdown on overload (latched or autorestart)
- Transformer saturation detection
- Programmable frequency modulation for EMI reduction
- Latched or autorestart OVP
- Brownout protection
- -600/+800 mA totem pole gate driver with active pull-down during UVLO
Applications
- Hi-end AC-DC adapter/charger
- LCD TV/monitor, PDP
- Digital consumer, IT equipment
- Single-stage PFC
- Industrial SMPS
- SMPS running off rectified 3-phase input line
Q & A
- What are the primary modes of operation for the L6566B?
The L6566B supports both fixed-frequency (FF) and quasi-resonant (QR) operation.
- What is the maximum duty cycle in fixed-frequency mode?
The maximum duty cycle in FF mode is limited at 70% min.
- What is the high-voltage start-up capability of the L6566B?
The L6566B features an on-board 700 V high-voltage start-up.
- How does the L6566B manage light loads?
The L6566B has advanced light load management, including controlled burst-mode operation at very light loads.
- What protection features does the L6566B include?
The L6566B includes pulse-by-pulse OCP, transformer saturation detection, latched or autorestart OVP, brownout protection, and more.
- What is the quiescent current of the L6566B?
The quiescent current of the L6566B is less than 3 mA.
- What is the gate driver current capability of the L6566B?
The L6566B has a -600/+800 mA totem pole gate driver with active pull-down during UVLO.
- What are some common applications of the L6566B?
Common applications include hi-end AC-DC adapters, LCD TVs/monitors, digital consumer and IT equipment, and single-stage PFC.
- How does the L6566B mitigate EMI emissions?
The L6566B features programmable frequency modulation for EMI reduction.
- What package style does the L6566B come in?
The L6566B comes in an SOIC-16N package.
