PRODUCT DATASHEET
AAT2713
SystemPowerTM
Low Noise Dual 600mA Step-Down Converter with Synchronization
VIN
U1
C3
AAT2713
VIN1
EN1
4.7μF
5
16
9
VIN2
EN2
PS
10
11
1.8V
2.5V
1
VCC
L1
L2
7
14
3
LX1
LX2
FB2
2.2μH
3.3μH
4
6
2
8
FB1
R1
118k
R3
187k
12
15
13
N/C
MODE/SYNC
N/C
AGND
PGND1
R2
59.0k
C2
4.7μF
C1
4.7μF
R4
59.0k
PGND2
Figure 1: AAT2713 Typical Schematic.
Under-Voltage Lockout (UVLO)
PWM/LL Operation
Under-voltage lockout (UVLO) guarantees sufficient VIN
bias and proper operation of all internal circuitry prior to
activation. When the input voltage falls below 2.35V
(typ) the AAT2713 will stop regulation of the output.
For minimum ripple under light load conditions, the
MODE/SYNC pin should be tied to a logic high. For more
efficient operation under light load conditions the MODE/
SYNC pin should be tied to a logic low level. When
MODE/SYNC is logic high, the AAT2713 operates in
fixed-frequency mode under all load conditions. When
MODE/SYNC is logic low, the AAT2713 operates in fixed-
frequency PWM mode under heavy loads and light load
mode under light loads.
Fault Protection
For overload conditions, the peak inductor current is
limited. Thermal protection disables the converter when
the internal dissipation or ambient temperature becomes
excessive. The over-temperature threshold for the junc-
tion temperature is 140°C with 15°C of hysteresis.
Converter Clock Phase
A logic high on the PS pin while in PWM mode forces
both converters to operate 180° out of phase thus
reducing the input ripple by roughly half. A logic low on
the PS pin synchronizes both converters in phase.
w w w . a n a l o g i c t e c h . c o m
12
2713.2008.01.1.0
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
