AAT1276

• High Frequency Boost With 5V / 500mA Output Capability
From a Single-Cell Lithium-Ion/Polymer Battery
• Input Voltage Range: 2.7V to 5V
• VOUT1 Adjustable or Fixed (5V)
• >90% Efficiency
• Up to 2MHz Switching Frequency
• True Load Disconnect
• Load Switch With Programmable Current Limit
• Over-Temperature, Over-Current Protection
• Inrush Current Limit
• Fault Report
• Low Shutdown Current < 1A Typical
• -40 to +85 Temperature Range
• TSOPJW-12 and TDFN34-16 Packages

The AAT1276 SwitchReg is a 2MHz, 500mA synchronous boost converter with an integrated current-limiting load switch controlled output. The AAT1276 operates from a single-cell Lithium-ion/ polymer battery source and provides a regulated 5V, current limit controlled output to support USB port VBUS applications in portable consumer electronic products. The AAT1276 can support both USB 2.0 host port and USB on-the-go operation, as well as general purpose applications where a 5V supply with a user programmable current limit is needed.

The high efficiency boost converter section of the AAT1276 is typically set for a 5V output and can deliver up to 500mA load current to support USB VBUS operation from an input supply as low as 2.7V. The high boost converter switching frequency (up to 2.0MHz) provides fast load transient and allows the use of small external components. Fully integrated control circuitry simplifies system design and reduces total solution size.

The integrated, programmable current limiting load switch provides USB port protection for portable devices allowing the AAT1276 to supply a 5V USB VBUS up to 500mA. The load switch provides an active low fault flag to alert the system in the event of an over-current condition applied to the AAT1276 output.

The AAT1276 is available in the Pb-free, space-saving 12-pin TSOPJW and 16-pin TDFN34 packages and is rated over the -40 to +85 operating temperature range.