Overview
The L6565D, produced by STMicroelectronics, is a current-mode primary controller IC designed for building offline Quasi-resonant ZVS (Zero Voltage Switching at switch turn-on) flyback converters. This IC is optimized for high efficiency and compliance with various energy standards such as Blue Angel, Energy Star, and Energy 2000. The quasi-resonant operation is achieved through a transformer demagnetization sensing input that triggers the MOSFET's turn-on, ensuring efficient switching. The device also features line voltage feedforward to maintain constant power delivery despite changes in mains voltage and a frequency foldback mechanism to optimize standby efficiency at light loads.
Key Specifications
| Parameter | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|
| Supply Voltage (Vcc) | 10.3 | - | 18 | V |
| Turn-on Threshold (VccOn) | 12.5 | - | 14.5 | V |
| Turn-off Threshold (VccOff) | 8.7 | - | 10.3 | V |
| Hysteresis | 3.65 | - | 4.3 | V |
| Start-up Current | 45 | 70 | - | µA |
| Quiescent Current | 2.3 | 3.5 | - | mA |
| Operating Temperature | -40 | - | 150 | °C |
| Storage Temperature | -55 | - | 150 | °C |
| Gate Driver Peak Current | - | - | ±700 | mA |
Key Features
- Quasi-resonant (QR) Zero-Voltage-Switching (ZVS) topology for high efficiency
- Line feedforward to deliver constant power despite mains voltage changes
- Frequency foldback for optimum standby efficiency at light loads
- Ultra-low start-up current (< 70µA) and quiescent current (< 3.5mA)
- Disable function (ON/OFF control)
- 1% precision internal reference voltage (@ Tj = 25°C)
- ±400mA totem pole gate driver with UVLO pull-down
- Pulse-by-pulse and hiccup-mode overcurrent protection (OCP)
- Compliance with Blue Angel, Energy Star, and Energy 2000 standards
Applications
- TV/Monitor SMPS
- AC-DC adapters/chargers
- Digital consumer electronics
- Printers, fax machines, photocopiers, and scanners
Q & A
- What is the primary function of the L6565D IC?
The L6565D is a current-mode primary controller IC designed to build offline Quasi-resonant ZVS flyback converters.
- What is the significance of quasi-resonant operation in the L6565D?
Quasi-resonant operation is achieved through a transformer demagnetization sensing input that triggers the MOSFET's turn-on, ensuring efficient switching and high efficiency.
- How does the L6565D handle variations in mains voltage?
The device features line voltage feedforward to maintain constant power delivery despite changes in mains voltage.
- What is the purpose of the frequency foldback mechanism in the L6565D?
The frequency foldback mechanism optimizes standby efficiency at light loads by automatically lowering the operating frequency.
- What are the typical start-up and quiescent currents of the L6565D?
The start-up current is less than 70µA, and the quiescent current is less than 3.5mA.
- Does the L6565D have overcurrent protection?
- Is the L6565D compliant with any energy efficiency standards?
- What are the typical operating and storage temperature ranges for the L6565D?
The operating temperature range is -40°C to 150°C, and the storage temperature range is -55°C to 150°C.
- What is the peak current capability of the gate driver in the L6565D?
The gate driver has a peak current capability of ±700mA.
- What are some common applications of the L6565D?
