AAT1156 Datasheet, PDF (2/14 Pages) Advanced Analogic Technologies – 1MHz 700mA Step-Down DC-DC Converter

AAT1156
1MHz 700mA Step-Down DC-DC Converter
Pin Descriptions
Pin #
1, 2, 3
Symbol
PGND
4
FB
5
SGND
6
LL
7
EN
8, 16
9
10, 11, 12
13, 14, 15
EP
NC
VCC
VP
LX
Function
Main power ground return pin. Connect to the output and input capacitor
return. (See board layout rules.)
Feedback input pin. This pin is connected to the converter output. It is
used to set the output of the converter to regulate to the desired value
via an internal resistive divider. For an adjustable output, an external
resistive divider is connected to this pin on the 1V model.
Signal ground. Connect the return of all small signal components to this
pin. (See board layout rules.)
Mode selector switch. When pulled low, the device enters light load mode.
Enable input pin. A logic high enables the converter; a logic low forces
the AAT1156 into shutdown mode, reducing the supply current to less
than 1µA. The pin should not be left floating.
Not internally connected.
Bias supply. Supplies power for the internal circuitry. Connect to input
power via low pass filter with decoupling to SGND.
Input supply voltage for the converter power stage. Must be closely
decoupled to PGND.
Connect inductor to these pins. Switching node internally connected to
the drain of both high- and low-side MOSFETs.
Exposed paddle (bottom); connect to PGND directly beneath package.
Pin Configuration
QFN33-16
(Top View)
PGND ¹
PGND ²
PGND ³
FB ⁴
12 _VP
11 VP
10 _VP
9 _VCC
2
1156.2005.11.1.2