PRODUCT DATASHEET
AAT1265
SwitchReg
TM
Low Voltage 2MHz Step-Up DC/DC Converter in SC70JW Package
Functional Block Diagram
VCC
VIN
OUT
Start-Up
Inrush Control
V
REF
Low Voltage
Start-Up
Voltage
Reference
Mode
Control
DH
2MHz
Oscillator
Logic
LX
Current
Sense
Comp.
DL
Error
Amp.
GND
EN
GND
Functional Description
The AAT1265 synchronous step-up converter is targeted
for single- or dual-cell alkaline, NiMH, and NiCd and
single-cell lithium-ion/polymer battery applications. It
has a 1V typical start-up voltage with operation after
start-up to less than 0.8V.
The high 2MHz switching frequency of the AAT1265
facilitates output filter component size reduction for
improved power density and reduced overall footprint. It
also provides greater bandwidth and improved transient
response over other lower frequency step-up converters.
The compensation and feedback is integrated with only
three external components (C
IN
, C
OUT
, L).
Low R
DS(ON)
synchronous power switches provide high
efficiency for heavy load conditions. Switching frequency
modulation and low quiescent current maintains this
high efficiency for light load and sleep mode conditions.
In addition to the improved efficiency, the synchronous
boost has the added performance advantage of true load
disconnect during shutdown (<1μA shutdown current),
inrush current limit, and short-circuit protection.
PWM / Light Load Control
The AAT1265 is a fixed frequency PWM peak current mode
control step-up converter. For light load conditions (10 to
20mA and below), the converter transitions to a variable
1265.2007.12.1.4
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