AAT2688 Datasheet, PDF (1/20 Pages) Advanced Analogic Technologies – 4.5A PMIC Solution for 12V Adapter Systems with 2-Output High Performance Step-Down Converters

DATA SHEET
AAT2688
4.5A PMIC Solution for 12V Adapter Systems
with 2-Output High Performance Step-Down Converters
General Description
The AAT2688 provides two independently regulated DC
outputs: a high voltage synchronous step-down (Buck)
regulator and a low input voltage step-down 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 of 6.0V to 24V, providing up to 4.5A output cur-
rent. 490kHz fixed switching frequency allows small L/C
filtering 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 low out-
put noise, low quiescent current, and excellent transient
response.
The step-down regulator includes integrated over-cur-
rent, soft-start and over-temperature protection. Inde-
pendent input and enable pins provide maximum design
flexibility.
The AAT2688 is available in the Pb-free 4mm x 5mm
24-pin TQFN package. The rated operating temperature
range is -40°C to 85°C.
Features
• 2-Output Step-Down Converters:
• Channel 1 (Buck): V_{IN1 = 6.0 to 24.0V}
▪ VOUT1 Adjustable from 0.8V to 5.5V
▪ IOUT1 up to 4.5A
▪ High Switching Frequency
▪ Voltage Mode Control
▪ High Accuracy ±1.5%
▪ PWM Fixed Frequency for Low Ripple
• Channel 2 (LDO): V_{IN2 = 2.7V to 5.5V}
▪ IOUT2 up to 600mA
▪ ^{1V Dropout Voltage at 600mA I}OUT
• Small Solution Size
• System on a Chip
• Ultra-small External L/C
• Shutdown Current <35μA
• Independent Enable Pins
• Over-Current and Over-Temperature Protection
• Internal Soft Start
• 4x5mm 24-Pin TQFN Low Profile Package
• -40°C to 85°C Temperature Range
Applications
• DSL and Cable Modems
• Notebook Computers
• Satellite Set-top Boxes
• Wireless LAN Systems
Typical Application
C3
0.1μF
D1
BAS16
J1
2
1
V_IN1
6.0V -24.0V
C14
2.2μF
+ _C1
220μF
25V
V_IN2
C13
1μF
25V
C2
2.2μF
L1 4.7μH/5.3A
LX1
BST1 ^DL
VL1 _RS1
OS1
IN1
FB1
Q1
C10
R2 C4
2.2nF
2K 220nF
R5
150
COMP1
AAT2688
R1
3.92k
C5
2.2nF
EN1
IN2 OUT2
C6
150pF
V_OUT2
EN2 GND
C12
2.2μF
TQFN45-24
V_OUT1
3.3V/4.5A
R3
9.09k
C7 C8
22μF 22μF
C9
22μF
R4
1.96k
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
202034A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • June 8, 2012
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