AAT2786 Datasheet, PDF (2/27 Pages) Advanced Analogic Technologies – 1.5A Step-Down Converter and 150mA LDO

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PRODUCT DATASHEET
AAT2786
1.5A Step-Down Converter and 150mA LDO
Pin Descriptions
Pin #
1, 2
3
4
5
6
7
8
9
10
11
12
13
14
15,16
Symbol
LX
PGND
GND
FB
LDOOUT
LDO_GND
BYP
LDO_EN
N/C
LDOIN
VIN
BUCK_EN
MODE/SYNC
VP
Description
Step-down converter switching node. Connect the output inductor to this pin. The switching node is
internally connected to the drain of both high- and low-side MOSFETs.
Step-down converter main power ground return pin. Connect to the output and input capacitor return.
Non-power signal ground pin.
Step-down converter feedback input pin. This pin is connected either directly to the converter output or
to an external resistive divider for an adjustable output.
LDO output pin; should be decoupled with 2.2µF ceramic capacitor.
LDO ground connection pin.
LDO bypass capacitor connection; to improve AC ripple rejection, connect a 10nF capacitor to GND. This
will also provide a soft start function.
LDO enable pin; this pin should not be left floating. When pulled low, the LDO PMOS pass transistor
turns off and all internal circuitry enters low-power mode, consuming less than 1µA.
Open
LDO input voltage pin; should be decoupled with 1µF or greater capacitor.
Step-down converter power supply. Supplies power for the internal circuitry.
Step-down converter enable pin. A logic low disables the step-down converter and it consumes less than
1µA of current. When connected high, it resumes normal operation.
Connect to ground for Light-Load/PWM mode and optimized efficiency throughout the load range. Con-
nect high for low noise PWM operation under all operating conditions. Connect to an external clock for
synchronization (PWM only).
Step-down converter input voltage for the power switches.
Pin Configuration
TDFN34-16
(Top View)
LX ¹
LX ²
PGND ³
GND ⁴
FB ⁵
LDOOUT ⁶
LDO_GND ⁷
BYP ⁸
16 _VP
15 _VP
14 _MODE/SYNC
13 _{BUCK_EN}
12 _VIN
11 LDOIN
10 _N/C
9 _{LDO_EN}
2
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2786.2008.04.1.0