EVL6566B-65W STMicroelectronics, EVL6566B-65W Datasheet - Page 6

• Manufacturer Part Number: EVL6566B-65W
• Description: BOARD EVAL FOR L6566B
• Manufacturer: STMicroelectronics

Specifications of EVL6566B-65W

• Main Purpose: AC/DC, Primary Side
• Outputs And Type: 1, Isolated
• Power - Output: 65W
• Voltage - Output: 12V
• Current - Output: 5.4A
• Voltage - Input: 90 ~ 265VAC
• Regulator Topology: Flyback
• Frequency - Switching: 80kHz
• Board Type: Fully Populated
• Utilized Ic / Part: L6566B
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6452

Description
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Description
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 (auto-
restart 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.
L6566B