AAT2505 Datasheet, PDF (1/26 Pages) Advanced Analogic Technologies – Dual Channel, Step-Down Converter/Linear Regulator

General Description
The AAT2505 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 cell lithium-ion / polymer batteries.
The LDO has an independent input pin and is capa-
ble of delivering up to 300mA of current. 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 features include low quiescent current, low
dropout voltage, and a Power-OK (POK) open drain
output signaling when V_OUT is in regulation.
The 600mA step-down converter is designed to
operate with 1.4MHz of switching frequency, mini-
mizing external component size and cost while
maintaining a low 27µA 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 with high voltage outputs,
the step-down converter duty cycle increases to
100%. The output voltage is either fixed or adjustable
with an integrated P- and N-channel MOSFET power
stage and 1.4MHz switching frequency.
The AAT2505 is available in a Pb-free, 12-pin
TDFN33 package and is rated over a temperature
range of -40°C to +85°C.
Typical Application
VIN = 2.7V to 5.5V
C3
10µF
3 _VP
VCC ⁴
3.3V at 300mA
5 _VLDO
9 _ENLDO
EN ¹⁰
LX ²
6
R3 100kΩ ₇
OUT
POK
FB ¹¹
SGND ¹²
C4
2.2 µF
8 _GND
PGND ¹
U1
AAT2505
2.5V at 600mA
L1
6.8µH
C1
4.7µF
L1 Sumida CDRH3D16-4R7 C1 Murata GRM219R61A475KE19
C3 Murata GRM21BR60J106KE19
2505.2006.06.1.1
AAT2505
Dual Channel, Step-Down
Converter/Linear Regulator
Features
SystemPower^™
• V_IN Range: 2.7V to 5.5V
• 300mA LDO
— 400mV Dropout Voltage at 300mA
— High Accuracy: ±1.5%
— Fast Line / Load Transient Response
— Power OK Output
• 600mA Step-Down Converter
— Up To 98% Efficiency
— 27µA No Load Quiescent Current
— Shutdown Current <1µA
— Low R_DS(ON) Integrated Power Switches
— Fast Turn-On Time (150µs Typical)
— Low Dropout 100% Duty Cycle
— 1.4MHz Switching Frequency
— Internal Soft Start
• Over-Temperature and Current Limit
Protection
• 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
100
90
80
70
60
0.1
Efficiency
(V_OUT = 2.5V; L = 6.8µH)
V_IN = 3.3V
1
10
100
Output Current (mA)
1000
1