AAT2687 Datasheet, PDF (1/20 Pages) Advanced Analogic Technologies – PMIC Solution for 24V Systems with 2 High Performance Step-Down Converters

DATA SHEET
AAT2687
PMIC Solution for 24V Systems
with 2 High Performance Step-Down Converters
General Description
The AAT2687 provides two independently regulated DC
outputs; consisting of a high voltage step-down regula-
tor and a low input voltage low dropout (LDO) regulator.
The PMIC is optimized for low-cost 12V adapter inputs,
making the device the ideal system-on-a-chip power
solution for consumer communications equipment.
Channel 1 is a step-down regulator with an input voltage
range 6.0 to 24V, providing up to 4.5A output current.
490kHz fixed switching frequency allows small L/C filter-
ing components. Channel 1 utilizes voltage mode control
configured for optimum performance across the entire
output voltage and load range.
Channel 2 is a low-dropout (LDO) regulator providing up
to 600mA output current. The device provides extremely
low output noise, low quiescent current and excellent
transient response.
The controller includes integrated cycle-by-cycle over-
current protection, soft-start and over-temperature dis-
able features. Independent input and enable pins pro-
vide maximum design flexibility.
The AAT2687 is available in the Pb-free, 4x5mm 24-pin
TQFN package. The rated operating temperature range is
-40C to 85C.
Features
• 2-Output Step-Down Converters:
▪ Channel 1 Step-Down: VIN1 = 6V to 24V
• V_{OUT1 Adjustable from 1.5V to 5.5V}
• I_{OUT1 up to 4.5A}
• High Switching Frequency
• Voltage Mode Control
• PWM Fixed Frequency for Low-Ripple
▪ Channel 2 (LDO): VIN2 = 2.7V to 5.5V
• I_{OUT2 up to 600mA}
• 1V Dropout Voltage at 600mA
• High Accuracy ±1.5%
• Small Solution Size
▪ ^{System On a Chip}
▪ Ultra-small External L/C
• Shutdown Current <35μA
• Independent Enable Pins
• Programmable Over-Current Protection
• Over-Temperature Protection
• Internal Soft Start
• 4x5mm 24-Pin TQFN Low Profile Thermally Enhanced
Package
• -40°C to 85°C Temperature Range
Applications
• DSL and Cable Modems
• Notebook Computers
• Satellite Settop Box
• Wireless LAN Systems
Typical Application
V_IN1
6.0V - 24.0V
J1 ²
1
C3
0.1µF
D1
BAS16
C14
2.2µF
+ _C1
220µF
25V
V_IN2
C13
1µF
25V
C2
2.2µF
LX1
BST
VL1 _RS1
OS1
IN1 FB1
L1
4.7µH 5.3A
D2
R2 C4
2k 220nF
C10
2.2nF
R5
450
V_OUT1
3.3V/4.5A
R3
8.87k
C7 C8 C9
22µF 22µF 22µF
COMP1
AAT2687
EN1
OUT2
IN2
EN2 GND
TQFN45-24
R1 C5
3.92K 2.2nF
C6
V_OUT2 ^150pF
1.8V/600mA
R4
1.96k
C12
2.2µF
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
202033A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 8, 2012
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