Date: 04/08/2011

Current limit protected 95% efficient step-down DC/DC Converter for USB 3.0 peripherals

Advanced Analogic Technologies Inc. has introduced the AAT2138, a DC/DC converter and efficiently regulate the power in USB peripherals, capable of supporting power levels beyond the USB 3.0 standard and offers a solution for a broad range of USB-powered devices including wireless modem data cards, portable hard drives or RAID systems, and card readers.

Key Features:
Input Voltage Range: 2.7V to 5.5 V
Output Voltage Range: Down to 3.0V
Low Quiescent Current: IQ = 90µA (Typ)
Current-Limited System Load Switch
Adjustable Current Limit Range: 500mA to 3A
1.5ms (Typ) Soft Start
±10% High Precision Current Limit
High-Current Step-Down Regulator
Efficiency up to 95%
85mOhm High-Side/50mOhm Low-Side FETs
2.8MHz (Typ) Switching Frequency
100% Low Dropout Operation.
No External Compensation Required
PFM/PWM or forced PWM Operation Mode
Supports a 1MHz to 3MHz External Clock
Optimized for small 1µH inductor
1ms (Typ) Soft Start
Independent Enable Pins
Over-Temperature and Over Load Protection
-40°C to +85°C Temperature Range

"USB 3.0, with its higher power capability, is enabling a host of peripheral devices that can run off USB power and do not require an AC/DC adapter," said Hensen Wong, Product Marketing Manager at AnalogicTech. "Consequently, peripheral system designers must take great care to make sure they safely maximize the power they receive from the USB host. By offering the safety of a precision current limit switch and the 95 percent efficiency of a DC/DC converter together in a single package, the AAT2138 enables system designers to develop small form-factor, energy efficient products that never exceed the compliance of the USB power supply, even under harsh transient conditions."

Available: Now
Package: 3mm x 3mm 14-pin TDFN package
Price; $1.19 for 1K units.