AAT1275_08 Datasheet, PDF (1/19 Pages) Advanced Analogic Technologies – Boost Converter with USB Power Switch

SwitchReg^TM
General Description
The AAT1275 SwitchReg is a 2MHz, 500mA synchronous
boost converter with an integrated current-limiting load
switch controlled output. The AAT1275 operates from a
single-cell Lithium-ion/ polymer battery source and pro-
vides a regulated 5V, current limit controlled output to
support USB port V_BUS applications in portable consumer
electronic products. The AAT1275 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
AAT1275 is typically set for a 5V output and can deliver
up to 500mA load current to support USB V_BUS 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 AAT1275 to supply a 5V USB V_BUS up to
500mA. The load switch provides an active low fault flag
to alert the system in the event of an over-current condi-
tion applied to the AAT1275 output.
The AAT1275 is available in the Pb-free, space-saving
12-pin TSOPJW and 16-pin TDFN34 packages and is
rated over the -40°C to +85°C operating temperature
range.
PRODUCT DATASHEET
AAT1275
Boost Converter with USB Power Switch
Features
• High Frequency Boost With 5V / 500mA Output
Capability From a Single-Cell Lithium-Ion/Polymer
Battery
• Input Voltage Range: 2.7V to 5V
• V_OUT1 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 < 1µA Typical
• -40°C to +85°C Temperature Range
• TSOPJW-12 and TDFN34-16 Packages
Applications
• USB On-the-Go
• Cell Phones
• Digital Still Cameras
• PDAs and Portable Media Players
• Smart Phones
• Other Hand-Held Devices
Typical Application
V_IN
Fault
Enable
C_IN
4.7µF
10k
R_SET
L1 2.2µH
LIN
IN
SW
OUT1
VCC
FB
AAT1275
FLT
EN
OUT2
SET
GND
R_FB1
432k
R_FB2
59k
C_OUT1
4.7µF
C_OUT2
1µF
V_BUS Output
1275.2008.04.1.7
www.analogictech.com
1