The ADP2105 / ADP2106 / ADP2107 are low quiescent current,
synchronous, step-down dc-to-dc converters in a compact 4 mm ×
4 mm LFCSP package. At medium to high load currents, these
devices use a current mode, constant frequency pulse-width
modulation (PWM) control scheme for excellent stability and
transient response. To ensure the longest battery life in portable
applications, the ADP2105 / ADP2106 / ADP2107 use a pulse
frequency modulation (PFM) control scheme under light load
conditions that reduces switching frequency to save power.
The ADP2105 / ADP2106 / ADP2107 run from input voltages of
2.7 V to 5.5 V, allowing single Li+/Li− polymer cell, multiple
alkaline/NiMH cells, PCMCIA, and other standard power sources.
The output voltage of ADP2105 / ADP2106 / ADP2107 is adjustable
from 0.8 V to the input voltage (indicated by ADJ), whereas the
ADP2105 / ADP2106 / ADP2107 are available in preset output
voltage options of 3.3 V, 1.8 V, 1.5 V, and 1.2 V (indicated by x.x V).
Each of these variations is available in three maximum current
levels: 1 A (ADP2105), 1.5 A (ADP2106), and 2 A (ADP2107).
The power switch and synchronous rectifier are integrated for
minimal external part count and high efficiency. During logic
controlled shutdown, the input is disconnected from the output,
and it draws less than 0.1 µA from the input source. Other key
features include undervoltage lockout to prevent deep battery
discharge and programmable soft start to limit inrush current at
startup.
Applications
- Mobile handsets
- PDAs and palmtop computers
- Telecommunication/networking equipment
- Set top boxes
- Audio/video consumer electronics
