AAT2514_08 Datasheet, PDF (7/14 Pages) Advanced Analogic Technologies – Dual Channel 600mA Step-Down Converter

SwitchReg^TM
Functional Block Diagram
FB1 ¹
600mV
+
EA
-
650mV
+
OVDET
-
+
ICOMP
-
EN1 ₂
EN2 ⁹
Bandgap
Reference
Overtemperature
and Shortcircuit
Protection
OSC
PRODUCT DATASHEET
AAT2514
Dual Channel 600mA Step-Down Converter
Slope Comp
Regulator 1
RQ
S _Q
+
I_SENSE
AMP
-
PWM
Logic
Non-
Overlap
Control
+
IZERO
COMP_-
POR
Counter
3 ^IN
4 _LX1
8 POR
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
www.analogictech.com
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