AAT2603_08 Datasheet, PDF (16/26 Pages) Advanced Analogic Technologies – Total Power Solution for Portable Applications

PRODUCT DATASHEET
AAT2603
Total Power Solution for Portable Applications
Functional Block Diagram
AIN
INB 2 INB 1
ENB 1
ENB 2
ENL 1
ENL 2
ENL 3
ENL 4
SELB 2
BYP
Interface
and
Support
DC-DC1
(Buck1)
DC-DC2
(Buck2)
LDO1
LX 1
FBB 1
PGND 1
LX 2
FBB 2
PGND 2
OUTL 1
FBL 1
INL12
LDO2
LDO3
OUTL 2
FBL 2
OUTL 3
FBL 3
INL34
AGND
LDO4
OUTL 4
FBL 4
Functional Description
The AAT2603 is a highly integrated voltage regulating
power management unit for mobile handsets or other
portable devices. It includes two switch-mode step-down
converters (600mA [DC-DC2] and 1.2A [DC-DC1]), and
four low-dropout (LDO) regulators (two: 200mA, two:
400mA). It operates from an input voltage between 2.7V
and 5.5V making it ideal for lithium-ion or 5V regulated
power sources. All six converters have separate enable
pins for ease of use.
Step-Down Converters
The AAT2603 switch-mode, step-down converters are
constant frequency peak current mode PWM converters
with internal compensation. The input voltage range is
2.7V to 5.5V. The output voltage range is 0.6V to V_IN.
The high 1.5MHz switching frequency allows the use of
small external inductor and capacitor.
The step-down converters offer soft-start to limit the
current surge seen at the input and eliminate output
voltage overshoot. The current across the internal
P-channel power switch is sensed and turns off when the
current exceeds the current limit. Also, thermal protec-
tion completely disables switching if internal dissipation
becomes excessive, thus protecting the device from
damage. The junction over-temperature threshold is
140°C with 15°C of hysteresis.
DC-DC1 (Buck1) is designed for a peak continuous out-
put current of 1.2A. The high-side power switch has
been designed with a low R_DSON of 145mΩ to allow for a
minimum dropout voltage of 174mV at full load current.
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2603.2008.10.1.2