iWatt announced the iW1700 Zero Power AC/DC Digital PWM Controller. The controller is designed to enable low-cost, energy-efficient 120V/230VAC 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. The company’s adaptive digital PWM/PFM technology sends the controller into sleep mode when the load is disconnected, cutting no-load power consumption to less than 4 mW, or effectively zero. Enabled by digital techniques, the iW1700 features primary-side control to eliminate an opto-coupler, quasi-resonant switching for low EMI, cycle-by-cycle waveform analysis, and a high (up to 72 kHz) switching frequency to achieve no-load charger performance. The controller seamlessly eliminates no-load power waste without a relay switch or microcontroller uses proprietary digital algorithms to switch between PWM and PFM modes multiple times as the end device charges. This approach eliminates audible noise, improves efficiency, and reduces switching losses by operating at a pre-determined minimum frequency at no-load. When the load is disconnected, the controller enters sleep mode and turns off non-essential circuits. The device also includes an active start-up function which disconnects the start-up resistor after the IC powers up.
iWatt
408-374-4200, www.iwatt.com