PRODUCT DATASHEET
AAT2514
SwitchReg
TM
Functional Block Diagram
Regulator 1
Slope Comp
Dual Channel 600mA Step-Down Converter
+
I
SENSE
AMP
3
IN
-
600mV
+
EA
-
+
I
COMP
-
S _Q
R
Q
PWM
Logic
FB1
1
Non-
Overlap
Control
4
LX1
650mV
+
OVDET
-
+
I
ZERO
COMP
-
8
EN1
EN2
2
9
Bandgap
Reference
Overtemperature
and Shortcircuit
Protection
POR
Counter
POR
OSC
FB2 10
REGULATOR 2 (Same as Regulator 1)
7
LX2
Functional Description
The AAT2514 is a dual high performance 600mA, 1.5MHz
fixed frequency monolithic switch-mode step-down con-
verter which uses current mode architecture with an
adaptive slope compensation scheme. It minimizes exter-
nal component size and optimizes efficiency over the com-
plete load range. The adaptive slope compensation allows
the device to remain stable over a wider range of inductor
values so that smaller values (1μH to 4.7μH) with associ-
ated lower DCR can be used to achieve higher efficiency.
Apart from the small bypass input capacitor, only a small
L-C filter is required at each output. The adjustable out-
puts can be programmed with external feedback to any
voltage, ranging from very low output voltages to the
input voltage and by using an internal reference of 0.6V.
The part uses internal MOSFETs for each channel to
achieve high efficiency. At dropout, the converter duty
cycle increases to 100% and the output voltages track
the input voltage minus the low R
DS(ON)
drop of the
P-channel high-side MOSFETs. The converter efficiency
has been optimized for all load conditions, ranging from
no load to 600mA at V
IN
= 3V with an input voltage range
from 2.5V to 5.5V. The internal error amplifier and com-
pensation provides excellent transient response, load,
and line regulation. Internal soft start eliminates any
output voltage overshoot when the enable or the input
voltage is applied.
2514.2008.02.1.1
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