OB2362AMP

General Description

OB2362 is a high-performance flyback PWM controller with adaptive multi-mode CCM/QR control, optimized to achieve high efficiency and low standby power while maintaining an economical system cost.

At heavy load and low-line input voltage, the IC operates in fixed-frequency CCM mode at 65 kHz.

At medium load, it operates in Quasi-Resonant (QR) mode.

At light load, the controller operates in Green Mode with Valley Skip.

At no load, the IC enters an extended Burst Mode to minimize switching losses and standby power consumption.

This multi-mode operation provides high conversion efficiency over a wide load range while minimizing standby power.

Operating Modes

Key Features

• Power-on soft start to reduce MOSFET VDS stress.
• Adaptive multi-mode operation.
• CCM operation at heavy load and low line.
• Quasi-Resonant operation at medium load.
• Green Mode with Valley Skip at light load.
• Burst Mode at no load.
• Frequency shuffling for improved EMI performance.
• Extended Burst Mode for improved efficiency and low standby power.
• Audio-noise-free operation.
• Low VCC startup current.
• Low operating current.
• Comprehensive protection functions.
• VCC UVLO with hysteresis.
• VCC over-voltage protection.
• Cycle-by-cycle over-current protection.
• Constant output-power limiting over a universal input-voltage range.
• Over-load protection with auto-recovery.
• External OTP using an NTC connected to the PRT pin, or internal OTP.
• Latched shutdown for OTP.
• Output over-voltage protection with latched shutdown.
• Adjustable Output OVP threshold using a resistor connected between the auxiliary winding and PRT pin.
• Output diode short-circuit protection with auto-recovery.
• SOT23-6 package.

Protection Functions

OCP — Cycle-by-Cycle Over Current Protection
Limits the primary-side current on every switching cycle and provides output-power limiting.

OLP — Over Load Protection
Provides protection against excessive load conditions with automatic recovery.

UVLO — Under Voltage Lockout
Prevents normal controller operation when VCC is too low. Hysteresis is provided for stable startup and shutdown behavior.

VCC OVP
Protects the controller against excessive VCC voltage.

OTP — Over Temperature Protection
Provides thermal protection with latched shutdown. OTP can be implemented using the internal temperature sensing function or an external NTC connected to the PRT pin.

Output OVP
Provides latched protection against excessive output voltage. The OVP trigger level can be adjusted using a resistor connected between the transformer auxiliary winding and the PRT pin.

Output Diode Short Protection
Detects a shorted output diode and provides automatic recovery.

EMI and Acoustic Noise

The OB2362 uses On-Bright's proprietary frequency-shuffling technique to improve EMI performance.

The controller also minimizes energy below 25 kHz, helping eliminate audible noise during normal operation.

Applications

• Offline AC/DC flyback converters.
• Power adapters.
• Set-Top Box power supplies.
• Open-frame SMPS.

Package

SOT23-6, 6-pin RoHS-compliant package.

Tags: OB2362AMP, OB2362A, PWM controller, Flyback, AC/DC, SMPS, 65kHz, SOT-23-6, On-Bright