AAT2786 Datasheet, PDF (14/27 Pages) Advanced Analogic Technologies – 1.5A Step-Down Converter and 150mA LDO

SystemPower^TM
Functional Block Diagram
PRODUCT DATASHEET
AAT2786
1.5A Step-Down Converter and 150mA LDO
VIN
MODE/SYNC
GND
BUCK_EN
LDO_EN
BYP
Oscillator
Bias
VP
LX
PGND
FB
LDOIN
RLDOFB1
LDOOUT
RLDOFB2
Functional Description
The AAT2786 is a dual output power solution. It includes
a 1.5A, 1.4MHz, high-efficiency step-down converter and
a high performance 150mA LDO regulator. The step-
down regulator output voltage is adjustable from 0.6V to
V_IN. The LDO regulator has a factory preset fixed output
voltage from 1.2V to 3.3V. The on and off states of the
step-down converter and the LDO regulator are indepen-
dently controlled by separate enable pins.
LDO_GND
Step-Down Converter
The step-down converter in the AAT2786 is a high perfor-
mance 1.5A monolithic step-down converter operating at
1.4MHz switching frequency. It minimizes external compo-
nent size and optimizes efficiency over the complete load
range. Apart from the small bypass input capacitor, only a
small L-C filter is required at the output. Typically, a 3.3µH
inductor and a 22µF ceramic capacitor are recommended
for a 3.3V output (see table of recommended values).
14
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2786.2008.04.1.0