AAT2500 Datasheet, PDF (1/26 Pages) Advanced Analogic Technologies – 1MHz Step-Down Converter/LDO Regulator

AAT2500
1MHz Step-Down Converter/LDO Regulator
General Description
The AAT2500 is a member of AnalogicTech's Total
Power Management IC™ (TPMIC™) product fam-
ily. It is a low dropout (LDO) linear regulator and a
step-down converter with an input voltage range of
2.7V to 5.5V, making it ideal for applications with
single lithium-ion/polymer batteries.
The LDO has an independent input and is capable
of delivering up to 300mA. The linear regulator has
been designed for high-speed turn-on and turn-off
performance, fast transient response, and good
power supply rejection ratio (PSRR). Other fea-
tures include low quiescent current and a low
dropout voltage.
The 400mA step-down converter is designed to
minimize external component size and cost while
maintaining a low 25µA no load quiescent current.
Peak current mode control with internal compen-
sation provides a stable converter with a low equiv-
alent series resistance (ESR) ceramic output
capacitor for extremely low output ripple.
For maximum battery life, the step-down converter
increases to 100% duty cycle and has a typical
180mV dropout voltage at 400mA. The output volt-
age is either fixed or adjustable with an integrated
P- and N-channel MOSFET power stage and
1MHz switching frequency.
The AAT2500 is available in a 12-pin TDFN33 or
STDFN33 package, and is rated over a tempera-
ture range of -40°C to +85°C.
Features
SystemPower^™
• V_IN Range: 2.7V to 5.5V
• 300mA LDO Current Output
• 400mV LDO Dropout Voltage at 300mA
• High Output Accuracy: ±1.5%
• Fast LDO Line / Load Transient Response
• 400mA, 96% Efficiency Step-Down Converter
• 25µA No Load Quiescent Current for Step-
Down Converter
• Shutdown Current <1µA
• Low R_DS(ON) 0.4Ω Integrated Power Switches
• Low Dropout 100% Duty Cycle
• 1MHz Switching Frequency
• Internal Soft Start
• Over-Temperature Protection
• Current Limit Protection
• Available in TDFN33-12 or STDFN33-12
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
VIN = 2.7V to 5.5V
C3
10μF
3.3V at 300mA
C4
2.2 μF
C5
10nF
3 _VP
VCC ⁴
5 _VLDO
EN ¹⁰
9 _ENLDO
LX ²
6 _OUT
FB ¹¹
7 _BYP
SGND ¹²
8 _GND
PGND ¹
U1
AAT2500
2.5V at 400mA
L1
4.7μH
C1
4.7μF
L1 Sumida CDRH3D16-4R7 C1 Murata GRM219R61A475KE19
C3 Murata GRM21BR60J106KE19
AAT2500 Step-Down Converter Efficiency
100
95
90
85
80
75
70
65
60
0.1
2.5V
1.8V
V_IN = 3.3V
1
10
100
1000
Load Current (mA)
2500.2006.05.1.16
1