Datasheet ADP2108 (Analog Devices)

Compact, 600 mA, 3 MHz, Step-Down DC-to-DC Converter Data Sheet ADP2108 FEATURES GENERAL DESCRIPTION Peak efficiency: 95%
The ADP2108 is a high efficiency, low quiescent current step-
3 MHz fixed frequency operation
down dc-to-dc converter manufactured in two different
Typical quiescent current: 18 μA
packages. The total solution requires only three tiny external
Maximum load current: 600 mA
components. It uses a proprietary, high speed current mode,
Input voltage: 2.3 V to 5.5 V
constant frequency PWM control scheme for excellent stability
Uses tiny multilayer inductors and capacitors
and transient response. To ensure the longest battery life in
Current mode architecture for fast load and line
portable applications, the ADP2108 has a power save mode that
transient response
reduces the switching frequency under light load conditions.
100% duty cycle low dropout mode
The ADP2108 runs on input voltages of 2.3 V to 5.5 V, which
Internal synchronous rectifier
allows for single lithium or lithium polymer cell, multiple alkaline
Internal compensation
or NiMH cell, PCMCIA, USB, and other standard power sources.
Internal soft start
The maximum load current of 600 mA is achievable across the
Current overload protection
input voltage range.
Thermal shutdown protection Shutdown supply current: 0.2 μA
The ADP2108 is available in fixed output voltages of 3.3 V, 3.0 V,
Available in
2.5 V, 2.3 V, 1.82 V, 1.8 V, 1.5 V, 1.3 V, 1.2 V, 1.1 V, and 1.0 V. All
5-ball WLCSP
versions include an internal power switch and synchronous rect-
5-lead TSOT
ifier for minimal external part count and high efficiency. The
Supported by ADIsimPower™ design tool
ADP2108 has an internal soft start and is internal y compensated. During logic controlled shutdown, the input is disconnected
APPLICATIONS
from the output and the ADP2108 draws less than 1 μA from
PDAs and palmtop computers
the input source.
Wireless handsets
Other key features include undervoltage lockout to prevent deep
Digital audio, portable media players
battery discharge and soft start to prevent input current over-
Digital cameras, GPS navigation units
shoot at startup. The ADP2108 is available in 5-ball WLCSP and 5-lead TSOT packages. The ADP2109 provides the same features and operations as the ADP2108 and has the additional function of a discharge switch in the WLCSP package.
TYPICAL APPLICATIONS CIRCUIT ADP2108 1µH 2.3V TO 5.5V 1.0V TO 3.3V VIN SW 4.7µF 10µF ON OFF EN FB GND
003 07375- Figure 1.
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Document Outline Features Applications General Description Typical Applications Circuit Table of Contents Revision History Specifications Absolute Maximum Ratings Thermal Resistance ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Theory of Operation Control Scheme PWM Mode Power Save Mode Power Save Mode Current Threshold Enable/Shutdown Short-Circuit Protection Undervoltage Lockout Thermal Protection Soft Start Current Limit 100% Duty Operation Applications Information ADIsimPower Design Tool External Component Selection Inductor Output Capacitor Input Capacitor Thermal Considerations PCB Layout Guidelines Evaluation Board Outline Dimensions Ordering Guide