AAT2506
1MHz Step-Down Converter/LDO Regulator
2506.2005.12.1.0 1
SysPwr
™
Typical Application
AAT2506 Step-Down Converter Efficiency
(V
OUT
= 2.5V; L = 10µH)
Output Current (mA)
Efficiency (%)
60
70
80
90
100
0.1 1 10 100 1000
V
IN
= 3.3V
4.7µH
L1
C1
22µF
2.2µF
C4
10µF
C3
10nF
C5
PGND
1
LX
2
VP
3
VCC
4
ENLDO
9
EN
10
FB
11
SGND
12
VLDO
5
OUT
6
GND
8
BYP
7
AAT2506
U1
L1 Sumida CDRH3D16-4R7 C1 Murata GRM219R61A475KE19
C3 Murata GRM21BR60J106KE19
VIN = 2.7V to 5.5V
3.3V at 300mA
General Description
The AAT2506 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 AAT2506 is available in either a fixed version
with internal feedback or a programmable version
with external feedback resistors. It can deliver
600mA of load current while maintaining a low
25µA no load quiescent current. The 1MHz switch-
ing frequency minimizes the size of external com-
ponents while keeping switching losses low. The
AAT2506 feedback and control delivers excellent
load regulation and transient response with a small
output inductor and capacitor.
The AAT2506 is designed to maintain high efficien-
cy throughout the operating range, which is critical
for portable applications.
The AAT2506 is available in a 12-pin TDFN33
package, and is rated over a temperature range of
-40°C to +85°C.
Features
•V
IN
Range: 2.7V to 5.5V
•V
OUT
Range: 0.6V to V
IN
• 300mA LDO Current Output
• 400mV LDO Dropout Voltage at 300mA
• High Output Accuracy: ±1.5%
• Fast LDO Line / Load Transient Response
• 600mA, 97% Efficiency Step-Down Converter
• Fast Turn-On Time (100µs Typical)
• 25µA No Load Quiescent Current for Step-
Down Converter
• Shutdown Current <1µA
• Low R
DS(ON)
0.4Ω Integrated Power Switches
• 100% Duty Cycle Low Dropout Operation
• 1MHz Switching Frequency
• 100µs Typical Soft Start
• Over-Temperature Protection
• Current Limit Protection
• Available in 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