iWatt, a leading supplier of digital-centric power management integrated circuits (ICs), has launched two new pulse width modulation (PWM) controllers, claiming to have raised the bar for no-load standby power consumption and efficiency in 12W to 24W power adapter and charger applications. The iw1761 and iw1762 devices expand iWatt’s latest PrimAccurate controller platform, lowering power draw in standby mode to just 10mW at up to 12W output power (iW1761) and 20mW at up to 24W output power (iW1762).
Both controllers offer even lower standby power consumption than iWatt’s recently announced iW1699 and iW1760 with their respective 30mW (at 12W) and 50mW (at 40W) standby power consumption.
All four devices have been designed to exceed current energy standards in the markets in which the company competes, including the proposed stringent 2012 U.S. DoE(1)regulation requiring under 100mW AC/DC adapter standby power consumption and tighter efficiency requirements. Like the previous iWatt parts, both the iW1761 and iW1762 enable high power density in an ultra-small overall adapter size.
The iW1761 and iW1762 both meet the compact size and low power requirements of next-generation compact media tablet power chargers and adapters and they also offer significantly greener and smaller solutions for AC/DC power adapters in a wide range of electronic products that remain permanently plugged in to the wall in standby mode, including set top boxes, satellite receivers and home networking equipment.
In addition to very low standby power consumption, these new controllers provide good dynamic load response (DLR).
Power supplies that achieve low standby power typically do so by entering a standby operating mode. However, when a load is applied, they need to “wake up” quickly to keep the output voltage from dropping too low. Dynamic load response is determined by the speed at which the system wakes up and responds to changes in the power load. The iW1761 and iW1762 offer low standby power with good DLR, while the recently announced iW1699 and iW1760 give designers options for higher DLR performance.
“There are always trade-offs in power management design and in the case of power adapters and chargers, the trade-off between dynamic load response and standby power is critical,” said Zahid Rahim, vice president and general manager of iWatt’s AC/DC business unit. “All four devices in iWatt’s new PrimAccurate controller platform set a new standard for iWatt in reducing standby power consumption while at the same time maintaining good DLR. This gives our customers the choices and flexibility they need to optimise their systems to their specific design priorities.”
iWatt’s ultra-low standby power AC/DC controller platform employs the company’s patented PrimAccurate primary-side control. This technology uses proprietary digital algorithms to eliminate the need for a secondary side regulator and optical feedback isolator, lowering the total BOM cost, reducing the overall solution size, and improving reliability. PrimAccurate technology enables accurate control of the output over a wide range of operating conditions and ensures tight load and line regulation, along with full protection from fault conditions, without costly additional components.