AAT2511
Dual 600mA, 1MHz Step-Down DC/DC Converter
2511.2006.02.1.2 1
SystemPower
™
General Description
The AAT2511 is a member of AnalogicTech's Total
Power Management IC™ (TPMIC™) product fam-
ily. It is comprised of two 1MHz step-down con-
verters designed to minimize external component
size and cost. The input voltage ranges from 2.7V
to 5.5V. The output voltage ranges from 0.6V to the
maximum applied input voltage and is externally
adjustable.
Peak current mode control with internal compensa-
tion provides a stable converter with low ESR ceram-
ic output capacitors for extremely low output ripple.
Each channel has a low 25µA quiescent operating
current, which is critical for maintaining high effi-
ciency at light load.
For maximum battery life, each converter's high-
side P-channel MOSFET conducts continuously
when the input voltage approaches dropout (100%
duty cycle operation).
Both regulators have independent input and
enable inputs.
The AAT2511 is available in a Pb-free, thermally-
enhanced 12-pin TDFN33 package, and is rated
over the -40°C to +85°C temperature range.
Features
• Up to 97% Efficiency
• 25µA Quiescent Current Per Channel
•V
IN
Range: 2.7V to 5.5V
•V
OUT
Range: 0.6V to V
IN
• Output Current: 600mA
• Low R
DS(ON)
0.4Ω Integrated Power Switches
• Low Drop Out 100% Duty Cycle
• 1.0MHz Switching Frequency
• Shutdown Current <1µA
• Current Mode Operation
• Internal Reference Soft Start
• Short-Circuit Protection
• Fast Turn-On (100µs Typical)
• Over-Temperature Protection
• 3mm x 3mm, < 1mm high
• TDFN33-12 Package
• -40°C to +85°C Temperature Range
Applications
• Cellular Phones
• Digital Cameras
• Handheld Instruments
• Microprocessor/DSP Core/IO Power
• PDAs and Handheld Computers
• Portable Media Players
Typical Application
AAT2511 Efficiency
(V
IN
= 3.3V)
Load Current (mA)
Efficiency (%)
60
65
70
75
80
85
90
95
100
0.1 1 10 100 1000
2.5V
1.8V
4.7µH
L1
10µF
C1
1.8V
118k
R1
59.0k
R2
10µH
L2
10µF
C2
2.5V
59.0k
R4
10µF
C3
V
IN
187k
R3
FB1
2
EN1
1
LX1
11
GND2
7
LX2
8
GND1
10
SGND1
3
VIN1
12
VIN2
9
SGND2
6
FB2
5
EN2
4
AAT2511
U1
0.1µF
C8