Paul O’Shea
iWatt, Inc., a developer of energy-efficient digital power supply control integrated circuits (ICs) used in leading-edge power supplies, announced the iW1700 Zero Power AC/DC Digital PWM Controller.
The iW1700 digital PWM controller targets 120/230-Vac offline adapters and chargers (up to 5 W), which consume zero no-load power for cell phones, audio players, digital cameras, and other low-power portable devices. It uses a patented adaptive digital PWM/PFM technology that sends the controller into sleep mode when the load is disconnected, cutting no-load power consumption to less than 4 mW.
The digital PWM controller uses digital techniques and features primary-side control and does not need an optocoupler. It eliminates audible noise, improves efficiency, and reduces switching losses by operating at a pre-determined minimum frequency at no-load. It is suitable for touchscreen smart phones and other portables that can be sensitive to common-mode noise. The device drives an external bipolar-junction-transistor power switch with lower common-mode noise than a MOSFET power switch. ($0.25 ea/10,000 — available now.)
