Power conversion chip saves on charger standby

Power Integrations has unveiled a 3W charger reference design that consumes less than 30mW of no-load power.

Power Integrations has unveiled a 3W charger reference design that consumes less than 30mW of no-load power.

Typical applications for this design include cellphones, cordless phones, PDAs, MP3 players and other battery-powered portable equipment.

The new design, DI-84, consumes 97% less no-load energy than traditional linear transformer-based power supplies (otherwise known as "energy vampires") and easily beats the recently announced mandatory regulations from the California Energy Commission (CEC), which permit up to 500mW of no-load energy consumption.

No-load power, the energy consumed by a charger or adapter when it's not powering a device but is still plugged into a wall socket, is considered a major source of energy waste, costing consumers billions of dollars annually.

The remarkable no-load power performance of the DI-84 is achieved through a combination of reducing the IC's internal power consumption, the low bias current design of the secondary feedback circuits, and efficient transformer design.

The 5V, 600mA charger is built around Power Integrations' popular TinySwitch-II power conversion IC family and operates over the universal input voltage range from 85 to 265V AC.

Besides providing a high level of energy efficiency, TinySwitch-II ICs also include safety and fault protection features not always found in lower-cost discrete MOSFET/PWM controller or ringing choke convertor (RCC) circuit designs.

These features include overvoltage protection, undervoltage lockout and hysteretic thermal shutdown that protects the entire circuit from over-temperature faults.

Additionally, this cost-effective solution easily meets CISPR-22 Class B conducted EMI limits without requiring a Y capacitor, contributing to the circuit's low component count and manufacturing cost and eliminating undesirable "touch current" in applications such as metal-encased cellphones.

"The sheer number and ubiquity of products that use external chargers and adapters makes their overall contribution to energy waste significant", said Doug Bailey, Vice President of Marketing at Power Integrations.

"The DI-84 low power charger design will allow manufacturers to rapidly bring products to market that exceed all worldwide mandatory and advisory efficiency and standby power consumption regulations".

This best-in-class design is available for downloading from the company website and represents another step in Power Integrations' ongoing mission to eliminate the energy wasted in the billions of chargers and adapters that are sold each year.

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