LD7576 Green-Mode PWM Controller IC

LD7576 Green-Mode PWM Controller IC is a current-mode PWM controller designed for offline AC/DC switching power supplies, adapters, battery chargers, open-frame SMPS circuits, and LCD/TV power supplies. It integrates a high-voltage 500 V startup circuit, green-mode power-saving control, UVLO, OVP, OTP, OLP, leading-edge blanking, internal slope compensation, and a 500 mA gate-drive output.

The LD7576 series is particularly useful when designing or repairing compact, cost-sensitive SMPS circuits where reduced standby power consumption and integrated protection functions are important.

LD7576 Green-Mode PWM Controller IC from Leadtrend is an offline switching power supply controller designed for efficient and reliable AC/DC power conversion. It uses current-mode PWM control and includes an integrated 500 V high-voltage startup circuit, reducing the need for an external startup circuit in suitable designs.

The controller features Green Mode operation for reducing switching activity under light-load or no-load conditions. Leadtrend uses a dual-oscillator approach to control the green-mode frequency and help avoid audible-noise problems commonly associated with low-frequency burst operation.

For power-supply protection, LD7576 incorporates under-voltage lockout, VCC over-voltage protection, over-temperature protection, and over-load protection. It also provides leading-edge blanking on the current-sense input and internal slope compensation, helping simplify the external SMPS control circuitry.

LD7576 is suitable for SMPS repair, AC/DC adapter development, battery charger circuits, open-frame power supplies, LCD power supplies, TV power supplies, and electronics laboratory projects. The LD7576 family is available in DIP-8, SOP-8 and SOP-7 variants depending on the specific ordering code.

For Bangladeshi students, electronics engineers, technicians and DIY power-supply builders, LD7576 can be a useful PWM controller IC for studying and developing flyback SMPS and offline AC/DC converter circuits.

Key Specifications

The LD7576 and LD7576H versions are specified at 65 kHz, while LD7576J and LD7576K versions are specified at 100 kHz. H/K variants use latch protection, while the standard/J variants use auto-recovery protection.

Main Features

• 500 V high-voltage startup circuit
• Current-mode PWM control
• Green-mode power-saving operation
• Non-audible-noise green-mode control
• Under-voltage lockout
• VCC over-voltage protection
• On-chip over-temperature protection
• Over-load protection
• 500 mA gate-drive capability
• Leading-edge blanking on CS pin
• Internal slope compensation
• Adjustable over-load protection delay
• Compact 7/8-pin package options
• Suitable for offline switching power supplies

Pin Description

For the common LD7576 8-pin configuration: