AnalogicTech’s High Voltage Step-down Converters Boost Power Efficiency of Networking, Wireless LAN Equipment
(Technology News, 28 Aug 2008 )
Advanced Analogic Technologies has introduced a new family of high voltage, high current, non-synchronous step-down converters capable of providing high efficiency power conversion from 24V supplies. Fabricated in AnalogicTech’s proprietary high voltage Modular BCD process, these new devices offer cost savings for wireless LAN, DSL and cable modem, and set-top box designs by integrating a buck converter with a low noise low dropout regulator (LDO).
Multiple Configurations Operating from an input voltage between 6.0V and 24V, the AAT1189 step-down converter is targeted at consumer electronics equipment operating from a low cost AC/DC adapter. It delivers up to 2.5A output current. A 490 kHz switching frequency allows designers to use smaller filtering components and keep total solution size small. The use of voltage mode control helps optimize performance across the entire load range.
The AAT2687 and AAT2689 combine a high voltage step-down converter with a low input voltage low dropout (LDO) regulator. The buck converters on both devices operate off a 6V to 24V input and deliver a VOUT of 1.5V to 5.5V. The buck converter on the AAT2689 delivers up to 2.5A. On the AAT2687 the buck converter supplies up to 4.5A. Like the AAT1189, the AAT2687 and AAT2689 take advantage of high frequency switching to support the use of smaller external filtering components.
The AAT2687 and AAT2689 devices feature an LDO capable of delivering 600 mA. The LDO offers low output noise, low quiescent current and excellent transient response. Separate enable pins allow the designer to independently control the buck converter and the LDO. Shutdown current is <15 µA.
